Purpose of this blog

Dmitry Yudo aka Overlord, jack of all trades
David Lister aka Listy, Freelancer and Volunteer

Sunday, September 25, 2016

Back to the Future?

Throughout the last few years I've seen a great many projects related to armoured warfare. Nearly every single one of them was scuppered by technological considerations. Either the technology was unavailable, or too cutting edge and so would cost too much. However with modern technology these ideas suddenly become feasible, in most cases tanks continue to be churned out looking much like the FT-17. So, let's consider some of the past projects and how they can fit in current warfare.

You might not know it, but there are laws to tank design. Break them and your tank will fail.This law is simple that there is a ratio of a tank's footprint, i.e. the surface of the track in contact with the ground, the track gauge. Both of these factors have an impact on the tanks width and length, lest you end up with something like a St Chamond from the First World War.
 This is because as a tank gets longer it gets harder to steer, as there's more track in contact with the ground. If you consider the tanks centre as a pivot point, and two parallel lines as the tracks in contact with the ground, then the edges of the tracks have the furthest to travel, equally they have the most resistance to overcome. As you make the length longer, you increase the footprint in contact with the ground, and thus the forces involved. Make a tank too short and it'll not be able to cross trenches, and it will lack stability. So you have to balance these requirements. The ideal ratio is about 1.3-1.8 times the width of the tank.

Now the length and width from the base of the tank also affect how high you can take the centre of gravity, take it too high and your tank will start to flip over. From this you can see that all three dimensions on a tank are related to each other.

Early tanks had a further trouble as they used skid steering. This is where one track is locked and the other drives dragging the tank around, this adds a massive anchor to one side of the tank. In Rhomboids of the first World War it was made worse by the two large gun sponsons right over the tracks. Another tank that broke this rule was the T-35. The engine used in the T-35 was the Mikulin M-17. This was also used in BT series and T-28's. While the latter two were not considered super reliable, they were vastly better than the T-35. The T-35 had between 49-51 units issued, in its combat tour in 1941 only five were lost to enemy action but 43 were lost due to mechanical breakdown. A large portion of those would be due to the over taxed engine just giving up.
Even today the ratio causes problems. The newest British IFV the Ajax has been accused by some commentators as being too long and too wide. This is a factor of the need to have enough length to fit infantry dismounts in the back.
 However by the 30's engineers were beginning to look at solving this issue, although they didn't know it. Giffard Le Quesne Martel, a famous British Army engineer officer that pioneered the use of tanks and bridging equipment, and who commanded the British at the Battle of Arras was in India and started looking at the problem. It was known that smaller tracked vehicles such as the Carden Loyd MG carrier steered just fine, but even the next step up, the light tank caused steering problems until a specialist gearbox was developed. But even then there was a theoretical maximum length to the light tank. He began to look at ways to make steering easier by making the tanks actually turn, like a truck, instead of skid steering.
His idea was to have four sets of tracks, two at the front and two at the rear. This four track set up has massive advantages in tank design. First it's much more stable, for example a bump or boulder would simply fit inside the gap in the tracks, where as a tank of the same length would still be rearing up until it tipped over. The tank would steer like a truck, which would make crew training a little bit easier. It also adds a bit of survivability to the tank, meaning it could theoretically continue to maintain some degree of mobility after a track was destroyed by a mine hit. Most importantly it disconnects the ratio of length vs width. In the case of an armoured vehicle carrying infantry it'd also give a useful position to mount a set of dismount doors in the side hull.
On these two images note where the doors hinges are located. This means they open out one each way, so that no matter which direction enemy fire is coming from you have an armoured door covering you as you dismount. Possibly a good idea for these side doors on the four track IFV?
In the last 40 years there have been at least two serious suggestions (that I know of) to make AFV's with four tracks. However these have all been shot down by more traditional officers who consider the idea too new fangled and too technical. But consider this. Martels prototype was hand built by himself in a shed at home, with 1930's technology. That was a tank with all four tracks driven mechanically, and it worked.  Hägglunds has been producing four track articulated all terrain vehicles, such as the BV-206, that have seen wide service throughout European militaries.
 In fact the concept of four tracks is actually easier now than it ever was, with the advent of hybrid electric drives you no longer need to run mechanical power to the track units, making maintenance and reliability even better. So maybe it's time to look at four track tanks again?

Another thing one sees a lot of in the 1980's is elevating ATGM platforms. Such as this German entry.
The arm erects to launch ATGM's across the battlefield, while the launching tank stays nice and safe.

Now the two main driving forces behind its cancellation was the end of the Cold War, and the massive elevating arm. That's a lot of weight in an AFV, and it also takes time to erect and the vehicle can’t move if it’s erected. However in the 1960's as part of the infamous Project Prodigal some bright chap suggested drones connected by radio to a tank to attack enemy targets. His sketch shows tiny helicopters linked to Centurions, flying above the tank platoon as it charges towards Soviet armour, the mini-helicopters are adding their fire-power to that of the Centurions resulting in a total rout of the enemy defences.
But what if we combine the two ideas? Quadcopters are getting pretty advanced, to the extent the average person can buy one cheaply. And look at Amazon's latest idea, drones delivering parcels. Beef the engines up a bit, and get them to carry a single ATGM. You get all the advantages of the arm mounted ATGM, without the negatives. You could for example have one of these drones lurking inside a building, where you'd not normally be able to mount ATGM's due to the problems of backblast. Or you could use a drone for reconnaissance, like a forward observation post, or similar roles such as ISTAR.

Another old British idea, that oh so nearly became reality that could help the modern British military, is that of liquid propellant. In the late 1950's and 1960's the British started studying liquid propellant. They even converted a couple of guns to test fire them. The main problem was that of uneven ignition of the propellant, which in turn gave wildly different muzzle velocities. If the issue of uneven ignition could be fixed then it could solve a huge issue facing the British Army.
At current our Challenger 2 tanks are getting old, and we can't replace the gun. To do so would mean ripping out the ammunition storage and that would pretty much require an entirely new tank, or at the very least an entirely new turret. The main driving force behind this is that tank penetrators have gotten longer to provide more penetrating power. Of course a longer penetrator is subject to more yaw force, which means it breaks up easier, but the general consensus from those in the know whom I trust is that the longer penetrator is better.
The current gun on the Challenger 2, called the L30, uses bag charges. On modern guns the penetrator extends down into the case of the round, which is something you cannot do with an L30.
So you have the issue of what to do. Well consider a new breech with more chamber space and a longer penetrator. Then consider a liquid propellant. The restrictions of the bag charge are removed, you could even create tanks to store the charge liquid in the same size and shape of the current charge bins, and the rod could be as long as is needed.
Charge bins in a Chieftian
You might even get advantages such as a higher rate of fire, or open the way for larger shells. As one big technical issue that people are bumping into is the next logical step up in tank calibre is to the 140mm. But the shells become so large you're limited to the number you can carry and hand loading is all but impossible.
When in the 80's it looked like the main tank gun calibre was to be 140mm, this is the autoloader the British developed.
When reading the above, however, the thing to consider is I'm no engineer. I'm a historian. So there could be massive technical problems, especially in the last idea, which mean the suggestions won't work in the real world. So please treat this article as just a set of casual observations.

My thanks to Maddest, for his help with this.

Image Credits:
www.fiddlersgreen.net, hmvf.co.uk, defense-update.com

Sunday, September 18, 2016

First and Only

The story of Finnish tanks during the Second World War isn't exactly a happy one. From a manpower point of view they did extremely well, with tank crews showing high levels of skill and courage. On the equipment side of things however the situation was dire. Finland had ordered 32 Vickers 6 ton MK.E's before the war, but to save money they'd been ordered without lots of fittings or equipment. They lacked any guns or sights, any radios, even the drivers seats were missing. By the time the Winter War broke out 26 tanks had been delivered. During the summer of 1939 the tanks were briefly armed with the 37mm guns loaned from Finland's FT-17's, so the Vickers tanks could be used in war games.
 After this time the FT-17's got their guns back and a program to arm the Vickers started. The tanks were fitted with a 37mm Bofors gun and water-cooled Maxim, both with improvised sights which reduced their accuracy. The driver curiously had a 9mm Suomi SMG fitted that he could use in place of a hull machine gun. This rearmament program continued during the Winter War. By late February 1940 thirteen tanks had been armed, and it was decided to send them into action. What followed was the one Finish tank attack of the Winter War.
Next to Lake Naykkijarvi (my spell checker just gave up and cried when I entered that name) lies the town of Honkaniemi. The attacking Soviets had pushed through the town, using the lake to screen their right flank. So it was decided that the 13 armed tanks which formed the 4th Tank Company would be launched into the salient and cut off the exposed Russians. Finnish Jaeger infantry was trucked to a site three km short of the assembly point at Jukkala. The infantry then skied the remaining distance arriving at 0400. The tanks were transferred by train to the front then unloaded and road marched 50 km to a staging area, arriving at 0430. However during that road march the Fins suffered their first losses. Five of the tanks had their fuel contaminated by water and broke down on the way. At the staging area a further two were put out of action with mechanical troubles. This left just six tanks for the attack.

The attack with several companies of infantry and two battalions of artillery in support was to cross a band of swampy terrain and slam into the Soviet front-line, tearing the top off the salient. Then the Finish infantry battalion at the head of the salient would pass through the counter attacking force and stop the penetration of Russian forces attempting to recapture the town. Don't be fooled by the description of "town", despite being the second largest settlement in the area it was mostly a combination of wooded areas and open cultivated fields with houses dotted about.
 The attack was scheduled for 0500 February 26th 1940, however communication issues with the supporting units meant the attack was postponed for an hour and fifteen minutes. Then when the artillery bombardment did begin some of the rounds landed short causing causalities in the Finnish force. Despite this the first ever Finnish armoured attack crossed its start line.
It failed to get off to a very auspicious start when tank 644 drove into a ditch and damaged the turret. Unable to fight the tank had to return to base.
Note the T-28 in the background. Likely a Vehicle Collection Point after the battle on the Soviet side.
Of the five remaining tanks all were destroyed, several whilst trying to inspire the infantry to follow them into close assaults. Three were destroyed in the lightly wooded areas. One, commanded by the platoon leader managed to reach a point where he could see the frozen lake on the other side of field. However his tank was hit and the crew forced to bail out. In return the Soviets lost at least three tanks, although the Soviet High Command claimed to have destroyed six enemy tanks for no loss.

Image credits:

Sunday, September 11, 2016

At the heart of the labyrinth

On a couple of occasions I have been to the Defence Capabilities Centre at Shrivenham (both times the visit was organised by Ed Francis). Some of the models they have are curious jobs that no-one has seen or heard of before. Equally you'll occasionally find a picture of a mysterious and strange model of a armoured fighting vehicle in British archives. These all come from one source, which has had many names throughout the years, but is best described by one of its names; The School of Tank Technology.
It is DCC Shrivenham’s fore runner, and was all about teaching soldiers about armour developments. One of the ways they did this was to set a course a mock specification and ask them to design a tank to fulfill this requirement. Some courses lasted only a few hours, others were much longer affairs lasting months. Today I'm going to talk about one such course and the design it came up with, the project was named Minotaur, and it came from the design exercise of 1950.

Another design exercise, this one called Taurus
Unfortunately we don't actually have a sketch or model of this design exercise. But we do have a detailed technical view, and the response by the people marking the work. From the description the tank seems to resemble a Jagdpanzer IV, only a 40 feet long, 10.25 feet tall and 13.3 feet wide Jagdpanzer IV! It weighed 75 tons, the upper superstructure front was slightly sloped at just 25 degrees, but was a fairly chunky 11" thick. The armour basis for this tank was 12".
The lower hull held the driver, with a domed hatch to give him sufficient headroom. Beside him was a co-driver with a small sub turret mounting twin Robinson machine guns to cover a blind spot. The commander had another sub turret with twin Robinson .30 machine-guns in it to provide local defence. The armour on these sub turrets is 4" thick, and each held 6000 rounds of ammunition for the machine guns. The MG's had a unique trait in that they ejected spent cases forwards, and so outside of the vehicle. Pretty much every other plate on the tank is a mere 2" thick, to provide protection against HE shell bursts and small arms. Interestingly the roof was a whopping 1.5" thick, normally you have less than an inch on the roof of most tanks. These plates also provided the structural strength to the tank. The rest of the tank was pretty boxlike with flat sides all the way around.

Now we move onto the main armament, and this is where things start to get interesting. The gun was a 180mm Lillywhite gun, and that's not a typo. It was another of the British big AT guns, much like the L4 183mm gun from the FV215b. The ammunition for this monster matched the dimensions and weight of the L4 183mm. Whether this gun was actually 183mm or 180mm I don't know, but if two guns had the same calibres the British had a habit of giving the other gun a different calibre in its designation to make sure the rounds for the two guns didn't get mixed up. The most famous version of this was the 77mm gun, which had the same calibre as the 17 pounder. Another example is the 95mm close support howitzer which shared a calibre with the earlier 15 lbr tank mortar.
The Lillywhite gun could be pulled back into the hull for movement, making the tank much more mobile. This did mean that the gunners controls were not directly linked to the gun, but to the hydraulic drives that controlled the gun. Speaking of which the gunner and commander were on opposite sides of the gun, which was a big departure from normal crew placements. The commander also had a naval style rangefinder which he'd then use to get a range and then pass the details over to the gunner. With this system an 80% hit chance was anticipated.
L4 183mm in the Fv4005 Stage I
The loading arrangements for the gun were also ingenious and unique. The huge nature of the Lillywhite’s rounds meant shell handling was tricky. First to get the rounds into the vehicle a removable derrick was provided. The ammo bins were on the floor raised slightly to provide room for drainage.
The next big issue was loading the gun, and this is possibly the bit that is the most ingenious. Around the back of the fighting compartment ran a conveyor belt. This was angled through a curve to match the position on the guns arc of 20 degrees either side of the centreline. On the belt were a series of loading trays each holding one complete round (the shell and two charge bags). This belt arrangement also elevated and depressed in line with the gun breech. The belt could be powered by one of the two loaders. An arm stuck out from the breech and when a loading tray hit the arm it automatically cut off the power to the conveyor. At this point the round contained within the loading tray was now aligned with the breech and if the loader wanted it loaded he'd just activate the power rammer. If he didn't want that round type he could override the cut off and keep the belt moving. This allowed rapid fire of the gun in any position for an extended period, as the conveyor belt had twenty loading trays! It was estimated the rate of fire would be six rounds per minute.
Same idea for the Minotaur, a derrick to winch the shells into the tank. Of course the Lillywhite shells are a little bit smaller.
The engine on the Mk.I Minotaur was a Rolls Royce Eagle engine that had been re-rated to 1400hp and was named "Nebula". A Mk.II Minotaur was planned with a gas turbine power pack producing 1300hp. Minotaur ran on four feet wide tracks.

So how well did they do when they submitted the design?
Generally their designs were considered acceptable, apart from two points.
The person assessing the firing accuracy summed it up by saying the tank would be slow to fire its first round, and would only have a 67% chance of hitting, which was below the required 80% on the specification. The other thing that they came in for some criticism on was for the basic premise they took of supplying such a large amount of armour at the expense of a turret. The assessor pointed out that the specification did not require armour protection to be as great as the students had made it. This in turn had led them to decide against a turret, which was a rather critical flaw in his view.

Image credits:
www.arcaneafvs.com and www.achtungpanzer.com

Sunday, September 4, 2016

Battle of the Yarra

HMAS Yarra was the second ship to bear that name. She was a Grimsby Class sloop, a tiny ship was lightly armed with only three four inch guns and a three inch gun along with a small compliment of automatic guns. She spent the first years of the war fighting in the Middle East against Italians, Iraqis and Iranians. During the Iraqi revolt she provided covering fire to Gurkhas as they launched an amphibious assault in locally acquired sailing boats. Her 4" shells smashed the Iraqi positions, often smashing through the houses she was firing at. Shortly after the Commonwealth achieved victory in the Middle East the Japanese attacked. HMAS Yarra was recalled to the Pacific.
On the 5th of February 1942 HMAS Yarra was part of a convoy escorting two troop ships to Singapore. The Japanese launched a massive air attack aimed at the two troop transports. Despite HMAS Yarra's barrage of fire the Japanese pilots pressed home the attack, setting both troop ships on fire. The first ship managed to get the flames under control, the second failed, and soon was a raging inferno amidships with the soldiers clustered fore and aft. During the height of the dive bombing attacks HMAS Yarra came alongside, the Japanese planes as well as dropping bombs were strafing the defiant sloop as she put a barrage of fire into the air. At 2000 yards range one Japanese plane was hit by the No.3 gun, receiving the captains praise. After the action the Captain also praised Acting Leading Seaman Ronald Taylor, whom commanded No.2 gun. The AA fire also claimed two probables.
While under this fierce unrelenting air bombardment, the stationary HMAS Yarra also rescued 1804 soldiers off the deck before the flames consumed the ship. The soldiers on the fore deck were taken off by other ships. The transport’s captain and his chief engineer were the last two to be evacuated from the foredeck. Now grossly overloaded the captain of HMAS Yarra ordered everyone who didn't need to stand to sit down. The survivors were then unloaded at Singapore, and were the last troops to arrive in the doomed city.
The ferocity of the gunfire laid down by the HMAS Yarra was such that her magazines were now over half empty.
Over the next few days HMAS Yarra was rushing about providing escorts for damaged ships and convoys. However on 11th of February seven personnel were detached from the ship. These men had served on board HMAS Yarra for up to 2.5 years, and were being returned to Australia. One of these men was the captain, Lieutenant Commander W.H. Harrington. He was replaced by Lieutenant Commander Robert W. Rankin. However there still hadn't been time to refill HMAS Yarra's empty magazines.
Lt.Cdr Rankin
The ship continued her duties until the 27th, when she was to lead a small convoy to Australia to evacuate the ships from the steadily worsening situation as the overpowering Japanese fleet pushed south. In the convoy HMAS Yarra was the most heavily armed ship. The rest of the convoy was made up of a tanker named Francol, the depot ship Anking and the minesweeper MMS.51.

What followed was two days of calm, apart from two incidents. The first excitement was spotting a single plane which couldn't be identified one evening, and then the next morning two lifeboats were sighted. These were attempting to sail for shore. Inside were the exhausted survivors of the Dutch ship Parigi, they had been in the boats for two days since their ship had been sunk.

At dawn of the 4th of March, 1942 the crew were at action stations. This was part of the normal daily routine. Together the crew watched the sun rise in a blaze of colour. They knew that with another day's sail they'd be safe in an Australian port. The men stood down, and the normal watches resumed. Then shortly later the the klaxon started to scream and the ship's company dashed back to their action stations.
The IJN Takao taken from the IJN Atago's deck.
A lookout had sighted the masts of three large warships. These hove over the horizon in the form of the IJN heavy cruisers Atago, Takao and Maya, accompanied by two destroyers. Each of these monsters had ten eight inch guns and armour up to five inches thick, and there was three of them. HMAS Yarra had three four inch guns and no armour.
Immediately Lt. Cdr. Rankin gave two orders. First he ordered the convoy to scatter and make best speed for safety. Next he had his radio room send a sighting report.

Then he turned his ship and charged the three giants.

As she charged forward HMAS Yarra laid smoke to try and cover the retreat of the convoy. The Japanese opened fire, almost instantly destroying Anking. Then HMAS Yarra returned fire, scoring a single hit on one of the cruisers. The Japanese force veered off and gave their full attention to HMAS Yarra. The initial volley that hit HMAS Yarra destroyed her No.1 and No.3 guns, sickbay and engine room. She was also listing heavily, with all her lifeboats smashed.
The other ships were sunk in short order, the tanker spewing flames and smoke all over the place giving a backdrop to events.

Knowing it was hopeless Lt. Cdr. Rankin gave the order to abandon ship moments before a follow up shell from the Japanese hit the bridge killing everyone there. One survivor was a rating who had just began to clamber down the ladder from the bridge when the shell hit, blowing him off the ladder and badly wounding him.
Ls Taylor
The senior surviving officer started to arrange the evacuation, some survivors started to launch Carley floats. At No.2 gun the crew heard the order to abandon ship. Leading Seaman Taylor heard the order, and dismissed his gun crew, stating he would continue to man the gun. Through the smoke he could see the two destroyers closing in on HMAS Yarra. By now her stern was under water. Eyewitnesses saw LS. Taylor’s gun begin to fire. After two or so rounds the gun took a direct hit silencing it forever. It is said that one of LS. Taylors shots hit one of the destroyers.
The last anyone saw of the HMAS Yarra was her sinking hulk being circled by two Japanese destroyers and a massive column of smoke.

34 survivors from HMAS Yarra were on those two Carley floats. Some were from the Dutch ship whom they'd rescued earlier. When the Dutch submarine K11 surfaced to recharge her batteries on the 9th of March, they spotted the survivors. By then wounds and exposure had reduced the survivors to just thirteen.
On the 4th of March 2014 the Australian Government awarded the HMAS Yarra a Unit Citation for Gallantry. Today the Royal Australian Navy has two ships in service linked to this fight, the HMAS Rankin and HMAS Yarra.

Image credits (and a more complete story):

Sunday, August 28, 2016

Vehicle of fire (Part two)

Part one.

Picture note: I ran into a bit of a problem hunting for pictures today... the Us didn't name the weapons, but the British did. Seeing as the document I was reading was British, it failed to mention the US designations, and so I'm taking guesses here.

Across the Atlantic the US were also looking at flame weapons and fitting them to tanks. At the time the report was written the Americans were working on three designs.
The Q. Gun was a modification to a M5A1 Stuart, interestingly it was designed so that everything was inside the turret, so all you needed to do in the field was swap a turret over. This was considered about 20 hours work. It replaced the 37mm gun with a dummy gun containing the flame gun. The 100 gallons of fuel, and the compressed gas were in the turret basket. The effective range for the gun was 100 yards, with a flow rate of two gallons per second. To make room for these the turret only contained one crewman.
The Klass Gun was a different matter with its fuel tanks in the sponsons of the tank, and so the entire tank had to be manufactured as single unit. Equally the pipe work running from the fuel tanks meant that the turret could only turn through, at best, 180 degrees unlike the 360 degrees of the Q. Gun. However the Klass Gun got an effective range of 120 yards, and a flow rate of 3.2 gallons per second. Fuel supply was also larger at 190 gallons. Interestingly the Klass Gun didn't have a dummy gun fitted, instead the nozzle was mounted directly into the gun mantle, making it look like an unarmed Stuart. The Klass Gun also only had a one man turret.
The Satan flamethrower... possible Klass gun?
The last design was still under development at the time the report was written, but it had some interesting features. Called the Indiana Gun it carried its fuel in a trailer. The compressed gas was air pumped in via a compressor powered by twin six cylinder aero engines. The flame gun was actually two guns, one designed for long range work, the other for short range work, and these were mounted in an external mount on the front hull. As it was still under development only the barest details are available, that the flow rate depending on which gun would be four or five gallons per second and the range was 125 yards. Its interesting to remember last weeks lesson about mixing compressed air in fuel tanks and how it makes them explosive, and one wonders how well this project would have progressed.
E9-9 possible Indiana Gun?
Back in the UK in 1944 the British started Project D.30, which may (although none of the documents mention this, but the dates do match as a precursor to the Salamander) have become the Sherman Salamander. It's basically fitting a British flame gun in the place of the main gun on a Sherman V. The fuel was carried in the hull, but to maintain the 360 degree turret traverse the fuel fed into a junction box at the base of the turret, this allowed the turret to keep its full rotation, an idea neatly borrowed from the German Panzer III flame tank. The tank was to be fully tropicalised, and one key component was the ability to use its flame gun during amphibious landings. It was clear Project D.30 was being created with an eye to dealing with the Japanese.
One requirement for Project D.30 was the ability to fire hydrocyanic acid instead of lit fuel. Now before you get ideas of dissolving the enemies, or even causing chemical burns, that wasn't the aim. Hydrocyanic acid also has several other names, which will give you an idea of what the aim was. One name is use during the period in other documents is "prussic acid". However the other name for it is this compounds most famous; Zyklon B. Yes, the ability to spray gas at the enemy was still in development as late as 1944. It's common in the 1930's when you see tanks for smoke laying or similar, but the trend seems to fall out of favour after the start of the war.
So what of the effects of a flame thrower? This is of some hot debate in tabletop wargaming circles. In one of my first articles that I wrote a long time ago for World of Tanks EU portal I mentioned a fight between a Crocodile and a Panther. In that article it says that the Crocodile hitting the Panther with its flame gun only immobilised it. I did check after I read it, the word I had in my original draft was "immolated". Obviously the WOT webmaster who edited it didn't know what the word meant and went for the closest word he understood. So yes a flame thrower will kill a tank.
What of dug in troops? Well the British did conduct trials on these, the first was carried out with a Wasp MK.I while the later trial was carried out by a Crocodile. One big difference between the two which may well account for the results was that the Wasp being an earlier version didn't have a nozzle on the end of the gun, the Crocodile did. In both trials enfilading shots on a linear obstacle, such as a slit trench or wall destroyed the position.
The Wasp Mk.I managed to knock out a position from a range of 40-60 yards, if a wet shot is fired first. The Crocodile managed from 80 yards with a single ignited shot. When moving they found it was impossible to hurt a trench if the occupiers kept their heads down. From these tests it was estimated how much fuel would need to be sprayed onto an area to achieve an effective hit or neutralisation.

Sunday, August 21, 2016

Vehicle of fire

Due to real life circumstances, and this article in its original form being quite a bit longer than anticipated, I'll be splitting it into two parts. 

Last week we had a look at handheld flamethrowers. Well the documents I read also covered vehicle mounted flamethrowers. This week, and next, I'll be covering those, although the information was only on Allied designs.

The British had the most famous vehicle mounted flamethrower, and it was the most efficient and successful. The following is a brief run down of the Crocodile so you can get an idea of its standards and then we'll have a look at some of the US designs.
The Crocodile started life as a Churchill Mk.VII infantry tank. An armoured trailer was attached to the back to carry the fuel and pressurisation gear, while an armoured channel ran along the underside of the tank. This channel had a plough attached to the leading edge to keep any debris away from the fuel pipe. The fuel pipe itself ran up through a hand-out hole, built into all Mk.VII's. This was normally used for cleaning and getting rid of waste. The hand-out hole was just behind the hull gunners position, from there this fuel line split into two pipes leading into the flame gun.
The flame gun itself was electrically powered with the tank commander having a control on the circuit. This enabled him to arm the gun or make it safe. The same circuit also allowed him to jettison the trailer.
The flame gun itself had three settings on it: "Safe", which rendered the trigger lifeless. "Ignition", which fired an ignited round, and just to be confusing, "Fire", which fired a unignited stream of fuel. The latter were termed "Wet" shots. The gun could elevate +15/-10 degrees and traverse seven degrees left and eleven to the right.
The six ton trailer was made out of 14mm armour plate, apart from the roof which was only 6mm. The 20" tyres were run flat designs and it had a ground clearance of one foot nine inches. The mount to the tank was a marvel of engineering. It allowed the trailer to rotate through 180 degrees in any direction, and still supply fuel, and could be jettisoned on command. When the trailer turned to far to the left or right a red or green light would light up in the driver's compartment informing him of the rotation of the trailer.
Inside the trailer lay five nitrogen bottles, each charged to 3000 lbs/sq. inch. These notoriously started leaking almost immediately and so charging was normally left to the last moment.  These all fed into a common hub which then fed into one of the fuel tanks.
Both the fuel tanks were located on either side of the trailer. They were seven feet, five inches long with a two foot six inch diameter. These contained the 400 gallons of fuel carried by the tank. Each fuel tank was linked in series, with the gas charge feeding in  the back of the series, and the fuel pipe to the flame gun out the front. Range was 140 yards and the Crocodile could fire between 80-85 shots, each lasting one second, this gave a discharge rate of about 4.5 gallons per second. To give you an idea of how much that is, that's about the same amount of water as comes out of a normal shower in three minutes fired out in one second.

Next week we'll have a look a three US projects, and another British flamethrower project. Plus the effect of flame throwers.

Sunday, August 14, 2016

Smoke and Fire

I've not done a technical article for a while, and not so long ago I found a document that went into flamethrowers in excruciating detail. The data is held in a British report gathered from the MI10 intelligence branch, which dealt with enemy equipment.
By 1941 the Germans were using a updated version of the 1935 model flamethrower, named unsurprisingly the Flammenwerfer 41. It had a nitrogen compressed gas tank above a fuel tank, with a wire braided pipe running to a hand unit. Above the hand unit was a 20 inch hydrogen tank used for ignition. This was held in place by what were described as clips like those used to attach a bicycle pump to its frame. However later a new improved version appeared. The British identified it as a Model 42, although the Germans don't seem to have had this designation. The main change was the type of ignition from hydrogen battery type to a cartridge type. The cartridges were 9mm rimless with a length of 22mm. They were angled about 27.5 degrees and aimed at the fuel jet which was 10mm away. When the trigger was pulled it would fire a cartridge and allow the fuel to flow. The new shorter hand unit held ten cartridges, and these were reloaded when the trigger was released. The spent round was ejected forward. Both the loading feed and the ejection system was described as "ingenious, but highly complicated" by the British intelligence assessment.
"Model 41" you can see the Hydrogen tube being used as a handle in this picture.
As well as German flamethrowers the document considered American designs and vehicle based designs and went into quite some detail on them. The US started the war with the M1A1, which weighed in at 63 pounds fully charged with its 4.5 gallons of fuel. The US then developed the E2 version which had a slightly improved flame gun and ignition system. One change was to the tank that allowed the fuel flow to be activated by the operator, on the earlier M1A1 the fuel flow had to be initialised by a second man.
M1A1, if you're never sure which version you're looking at, the M1A1 doesn't have a fore grip
Another change to the tank was the construction material. The M1A1's tank shattered under tests with a .30 cal armour piercing bullet. The E2's tank didn't. It wasn't judged an issue however as any round that hit the tank was almost certainly going to have hit the operator first, or so the theory went.
Now we come to the old story about flamethrowers exploding when hit. It was found that when compressed air was used instead of nitrogen the air mixed with the fuel vapours to make a flammable mix, however nitrogen was a lot harder to use logistically. Where as a E2 could just be wired up to a compressor the British and German models needed a separate source of compressed nitrogen. This would possibly explain why a German training manual stated:
"In order to give the men a greater sense of security attention should be drawn to the fact that should the weapon be struck by an infantry bullet or shell splinter it will not explode."
As British flamethrowers used the same methods of propulsion as the German ones, compressed nitrogen gas, then it's almost certain that the same would apply.
The US suffered another bout of exploding flamethrowers when they tried to develop a single shot flamethrower. The Germans had developed the Einstoss. This was a single shot flamethrower, a tube four inches in diameter and twenty four inches long. A cartridge when fired provided propulsion for the jet of fuel and ignition at the same time.
German Einstoss
The British developed a similar idea in the form of the snapshot flamethrower. Both of these used normal liquid fuel. The Americans however decided to use a self igniting powder called EWP. It appears to have been comprised of phosphorus as the ignition source with phosphorus sesquisulfide to provide the fuel. The latter is a component of match heads. The self detonating of the US single shot flame thrower came from the use of a cartridge with slow burning cordite to propel a piston that created the pressure and fired the powder out the end of the gun. Not all the powder was ejected, this lead to some of the explosions. Additionally the fuel ejection was found to be non uniform or consistent. The pressure was built by at first using a  stopper in the barrel of the US machine which would blow out at a certain point ejecting the flaming material. This gave inconsistent results however.
With all this in mind the weapon was redesigned. The EWP was contained in a collapsible tube with a frangible diaphragm at the muzzle, the piston powered by the charge now squeezed the package, and caused pressure to build that ruptured the diaphragm. The upshot of this design was the whole device could be re-loaded easily.
In the end the problems involved with creating the EWP and transporting it (a soft squidgy tube that if ruptured would burst into flames) seem to have killed off the project.
Lifebuoy Mk.II
The British at the time had three designs of flamethrowers, these were the Lifebuoy, the Ack-Pack and the Snapshot. The latter we've already discussed and it never seems to have gotten past a experimental stage, or if it did it seems to have been forgotten about by history. The Lifebuoy was the standard issue flamethrower used throughout the war by British forces. It was so named, or so the story goes, because it resembled a bar of lifebuoy soap. Of course it might be because it resembled an actual lifebuoy.
Lifebuoy soap in the 1940's... very slight resemblance.
The Ack-Pack was also known as the Para-Pack. As the name suggests it was a modified Lifebuoy that could be loaded into containers for dropping as part of airborne operations.

I've done some comparison tables for you:
The little data about the single shot weapons

Part two next week will cover tank mounted flamethrowers, and some rather horrific discoveries. It'll also tackle the question of how effective were flamethrowers.

Image credits:
www.militaryfactory.com, www.ww2incolor.com, www.canadiansoldiers.com and www.tgrantphoto.com

Sunday, August 7, 2016

North Sea Hijack

Esther, Ruth and Jennifer is a book by Jack Davies, it's about a hijack and blackmail attempt aimed at British North Sea oil production. It was later made into a film called North Sea Hijack (Renamed into Assault Force in the US... why?!). Well there's a little known episode that involved a platform in the North Sea, and it has such a charismatic cast it'd be worthy of Hollywood.

First we must skip backwards to the Second World War and the Naval Maunsell Forts I mentioned last week. One of these was emplaced at Rough Sands, and became, unsurprisingly, HM Fort Roughs. It was designated UNCLE-1, shortened to U-1. It was used until 1956 by the British government then abandoned.
HM Fort Roughs today.
Back in the 60's the national waters only extended three miles beyond the shoreline. Beyond that it was international waters, so Fort Roughs was in international waters, this proved a lucrative piece of dry land for pirate radio which had been outlawed by the Maritime Offences Act of 1967. However at the end of 1966 with the Act banning pirate radio transmissions from within the British territorial waters one of the pirate radio stations moved out to Fort Roughs, this was the famous Radio Caroline. However on Christmas Eve 1966 an Ex British Army major, Roy Bates and his son boarded Fort Roughs, grabbed the Radio Caroline's sentries air rifle and took over the tower. Later on when the Radio Caroline staff had been put ashore they returned and attempted to take over again. Bates responded with a Molotov cocktail which set the attackers boat on fire. From then on the Bates family were in control.
On the second of September 1967 Roy Bates declared the location the Principality of Sealand, an independent nation with himself and his family the royalty of the country. One of the first citizens was a German named Alexander Achenbach, who for some unspecified reason was given citizenship and the job title of Prime Minister for Life. As had been shown by the Radio Caroline incident the idea of land outside national laws was attractive to many businesses, Achenbach saw this location as an opportunity.
In August 1978 Achenbach arranged a proposition from a consortium of Dutch and German diamond merchants, they requested that Roy Bates and his wife fly to Austria to listen to a proposal. While there they met with five men who set a time for their meeting, but later never showed up.

Meanwhile at Fort Roughs the Bates’ son, Michael, was still in residence. A helicopter showed up and hovered over the fort and several German and Dutch mercenaries clambered down onto the fort armed to the teeth, Michael was quickly seized, bound and locked away. Later on a German lawyer, and citizen of Sealand, Gernot Pütz (yes, that's his real name) boarded the fort. Pütz was Achenbach’s personal lawyer. In effect it was a full blown coup.

After four days Michael was put ashore in the Netherlands where he met his father. Together they started to hatch a way to, in Roy Bates words, "[..]coup-d’étated the coup d’état!"
First they needed a way of getting to the fort. Enter one of the Bates family friends, one John Crewdson.
Crewdson was a pilot of no small skill. He'd flown one of the helicopters in the recent James Bond film On Her Majesty's Secret Service, even appearing briefly on screen. He'd also flown one of the B-17s in the film "The War Lover". He'd also flown one of two stripped out civilian helicopters that responded to the 1953 Dutch floods when the North Sea breached the flood defences, drowning 1300 people. In the subsequent relief operations, he rescued 76 people, transported two tons of emergency supplies and ferried forty four medical staff about.
Crewdson doing a pass in "The War Lover"
As you can see Crewdson was no stranger to low level flying. He put this to good use by flying alongside a passenger ferry, using the bulk of the ship to keep him from observation by the Sealand rebels. Then at the last moment he popped up over the ferry and raced in at full throttle coming to a hover over the fort. As Michael and Roy fast roped down, the rebels began to race out of the tower to repel boarders.
As Michael landed he stumbled and hit the floor, he was carrying a sawn off shotgun which accidentally discharged. The blast shocked the rebels who immediately surrendered. The coup was over.
From the left: Michael Bates, Joan Bates, Roy Bates and John Crewdson,
The rebels were mostly released apart from Pütz, who held a Sealand passport, and so was considered a traitor, and tried. A German diplomat flew out to Sealand to try to bargain for Pütz' release. Roy Bates set the release fee at 75,000 Deutsche Marks. Later on Roy Bates released Pütz, saying they'd all become a bit tired of him.
Achenbach set up the Sealand Government in Exile after his failed coup

Roy Bates died on 9th of October 2012, his wife on 10th March 2016, and John Crewdson died when his helicopter crashed into a sand bank on 26th June 1983.

Image Credits:

Sunday, July 31, 2016

Boats well Fort

Note: The account of the action on the night of the 22nd-23rd January, which is mentioned later in the article, comes from multiple sources. Many of these sources are confusing and contradictory. So the account is my best guess of the sequence of events.

In 1939 the Luftwaffe made a critical error, they dropped a new secret weapon, a magnetic mine, onto a sand bank off Shoeburyness in the Thames Estuary. This was quickly taken by the British and studied. 
The actual mine, just before removal.
Now alert to the threat of these magnetic mines the British commandeered wooden hulled paddle steamers from the Thames, armed them with a few guns and mine sweeping gear and began to use them to patrol and clear the estuary. Part of their job was also to drive off German aircraft, and prevent the mines being laid in the first place. It was obvious from the outset that a better permanent solution was needed.
The solution was a series of forts made from reinforced concrete and sunk onto sand bars. These would give a permanent stable base for AA Guns. The forts were designed by the Engineer Guy Maunsell, who was an expert in concrete. He designed two types of forts, the army and navy forts. The former was a collection of towers laid out in a pattern identical to a land based AA battery, these forts held several AA guns, radar and search lights which effectively extended the flak umbrella across the Thames Estuary. Two of three three forts survive today, although Shivering Sands Fort lost one of its towers. Red Sands Fort has been taken over by Project Red Sands.
The Naval forts were twin towered affairs with a deck that held a pair of 3.7" AA guns and some smaller close in AA guns such as 40mm Bofors guns and machine guns. Of the three of the Naval forts, only one survives today, as the Principality of Sealand.
All these forts were constructed the same way, on a concrete pontoon which was then floated out to position then flooded. The pontoon would become the foot of the fort and sink onto the sandbar providing a stable base.
A Naval fort being sunk in position. Note the Crew on deck during this operation.
During the Second World War these forts claimed twenty two German aircraft and thirty flying bombs. They also claimed to have sunk an E-boat.
 At 1753, on the 22nd of January 1945 several E-Boat flotillas were alerted to the likelihood of British convoys to Antwerp passing by and so were ordered to intercept. The boats of the 8th Schnellboatflotilla powered out of their bunker Ijmuiden, and turned towards the open sea. They encountered two separate aircraft and engaged them. The first after they took it under AA fire identified itself as a JU88, the second was a Whitley bomber, which they had a brief fight with to no effect on either side. They then reached their patrol zone.

Unknown to the Germans a British flotilla consisting of a control frigate (HMS Seymour) and several Motor Gun and Motor Torpedo Boats was closing on them. These patrol groups were set up to fight the E-Boat menace, the frigate, with its radar, provided command and control, as well as a massive whack of firepower. The motor boats were there to chase down the E-Boats.
At 0030 on the 23rd the E-boat flotilla picked up radar from a British ship, the sloop HMS Guillemot, and turned to attack. The E-Boats launched a single torpedo which missed and a brief, but intense, firefight erupted between the two sides. Hails of fire caused spurts of flame from the HMS Guillemot's bridge, and the return fire set a rubber life raft on one of the E-Boats on fire, unable to extinguish the fire they tossed the raft overboard.
Just before 0300 the E-Boats spot what turned out to be the British patrol group lead by HMS Seymour. The E-boats fired another single torpedo towards the British, who returned fire immediately, the E-Boats then broke away to the north before turning in for another salvo. This time the E-Boats put all eight of their remaining torpedoes in the water and again break away. At this point the Tongue Sands Fort begins to fire at the E-Boats with its twin 3.7" AA guns at a range of four miles.
 On the lead E-Boat the Germans spotted three British MGB's approaching at full power and only 200m away, two more groups of MGB's are closing from North West. The lead boat turned due eastwards to avoid the closest British MGB's, and the rest of the line followed. However during the ensuring short but vicious firefight with every weapon on both sides blasting away at point blank range the E-Boat S-199 and S701 collided (many sources say this collision was between MGB 495 and S701).

The impact was so severe the crew of S701 was thrown to the deck, staggering to their feet the crew saw the boat they hit as a shadow in the water to starboard. The impact caused severe flooding but S701 was able to maintain her speed. It also left a magazine for the forward gun, marked S199 on the deck of S701.

Bursting clear of the fire fight the remaining boats headed for home. Although two incidents further marred the deployment as two boats ran aground at speed on the treacherous sandbars that infest the area, it was only the rising tide that allowed them to float off. A third E-Boat hit floating debris and sprung a leak. This effectively put the entire flotilla out of action. The crew of S199 was rescued by the trawler Neave. On the British side MTB 495 took one shell to the engine room and Able Seaman George Calder, aged 21 from Edinburgh was killed, and the only causality of the fight on both sides.

Image Credits:

Sunday, July 24, 2016

Big Bang

On the 5th of July 1944 the 7146 ton Liberty Ship number 243756 left Hog Island in the US and began the long journey to the UK. Her first port of call was part of convoy HX-301. These convoys enjoyed a low loss rate, losing only 0.6% of all ships which used this crossing route. The reason for this was first the convoy went via Halifax, where they picked up more ships then took a long 3165 North East route to Liverpool. Even with an average speed of just 8.5 knots the 130 ships, including twelve US Landing Ships Tank, HX-301 reached Liverpool without enemy incident.
It is reported one of the escorts was an aircraft carrier, and that one of the transport ships had several young ladies on board. Upon finding out this fact the crew of the aircraft carrier put up a plane that dropped a gift of vegetables in a bouquet to the ladies on the transport. However the eyewitness says that this drop missed the ship and was last seen floating past.

Upon reaching Liverpool the convoy split and the ships went their own separate ways. Liberty Ship 243756 sailed for London, along with seven other Liberty Ships. Once reaching London they would hold until another convoy could be formed to cross the channel for the newly opened port at Cherbourg where her cargo of bombs, including several hundred blockbusters, would be unloaded to arm the RAF planes flying against Germany. Upon arrival at London she was assigned a mooring at the Great Nore Anchorage, covered by the Nore Forts.
These Maunsell Forts stick out of the sea on four giant legs, looking weirdly reminiscent of something from HG Well's War of the Worlds. Designed to protect the Thames Estuary from air and fast boats they were armed with a variety of AA guns, search lights and fire control centres. Each fort is linked by a walkway above the muddy sea. The concrete legs mounted on a base were floated out to be in position then sunk onto the sand banks. These sand banks were to cause the crisis.

Most Liberty Ships had a draft of about 28 ft. However ship 243756, named the SS Richard Montgomery, had a draught of 31 ft. The anchorage that was issued to the Richard Montgomery was a mere 33 ft deep. An argument broke out ashore at the control room for the area with the Harbour Master refusing the Assistant Harbour Master’s recommendation that the Richard Montgomery have her birth switched to a deeper one, currently occupied by a frigate. The frigate only had a draught of 24 ft. This argument became so heated that a superior naval officer intervened and sided with the Harbour Master.

On August 20th 1944 the wind changed direction, causing the Richard Montgomery to swing about, she then began to drag her anchor until inevitably she beached. Even worse she beached at the height of the spring tide which meant that even with removing all her ordnance she'd have to stay in position for several weeks before she could be re-floated.
Salvage efforts started on the 23rd of August, another ship came alongside and ran a steam hose aboard the Richard Montgomery to power the ship’s cranes. Then on the 24th the settling tides caused the Richard Montgomery’s back to break flooding several holds and letting some of the colossal amount of explosive contained within her holds to wash out onto the seabed. Salvage continued until late September when the operation was abandoned. So roughly 1400 tons of explosives lie in the mouth of the Thames Estuary, and have lain there since the end of the war. There is a debate over the question of the explosives still being viable or not. But what if they are?
SS Richard Montgomery as she is today. you can see where the currents have eroded the sand keeping her stable and upright.
Well we can look back to World War One to find a possible answer of what might happen. Coincidentally it happened at Halifax, the location Richard Montgomery’s convoy was named after. On 6th December 1917 the SS Mont-Blanc and the SS Imo collided in the Bedford Basin at about 0845. The collision toppled some barrels in the SS Mont-Blanc’s hull which split open spilling benzol, a highly inflammable liquid that caught fire from sparks caused during the impact.
The blaze spread throughout the ship and the crew were forced to abandon her. Some local boats tried to fight the fire after the SS Mont-Blanc beached itself. However at 0904 the fire reached the Mont-Blanc’s other cargo, explosives and guncotton for the French Army.
The Mont-Blanc exploded with the force of about 2.9 Kilotons! The blast vaporized so much water that the bottom of the harbour was briefly visible, and created a 18 meter Tsunami. The 90mm deck gun, melted out of shape was found 3.5 miles away and the shockwave was felt as far away as 129 miles. About 2000 people were killed, and 9000 injured.
The Halifax explosion, the cloud is nearly 12000 feet in height, so that gives you an idea of how far away this picture was taken.
One eyewitness and survivor described the scene. "The sight was awful, with people hanging out of windows dead. Some with their heads missing, and some thrown onto the overhead telegraph wires."
The Halifax explosion was in the middle of a single city in a sparsely populated country. The SS Richard Montgomery lies in the middle of one of the most densely populated regions.

Ground zero is to the extreme right of the picture. There's a sugar refinery in this picture...

Image credits:
dailymail.co.uk, bbci.co.uk, www.submerged.co.uk and exhibits.hsl.virginia.edu