Ram III tank

Quick review of OTL.
Americans first developed the reliable, full-tracked chassis that they hung under M-3 Lee, Grant and Sherman tank along with a variety of SP guns.
Early in WW2 Montreal Locomotive Works got a license to build tanks with American-pattern hulls, but the Ram I tank had a large-diameter turret ring, big enough for a British 6-pounder gun. The 6-pounder was a pretty good infantry-support gun firing HE. The 6-pounder could even be bored out to fire American 75 mm ammo (Churchill and post-war Dutch Ram IIs). But 6-pounder could not defeat Panzer 5 and 6.
After 1942, the excellent British 17-pounder AT gun was available, but never had an effective HE round. When the Brits re-trofitted 17-pounders to Shermans, they created the Sherman Firefly, Panzer-killer. The Commonwealth's leading tank ace: Major Radley-Walters used Fireflies to kill 17 Panzers of various vintages, including Panzer ace Michel Wittman.
MLW also built a few Sherman "Grizzly" cast hull, 75 mm gun, etc. but they were too busy building Sexton ASAP guns (25-pounder).
The Sherman's greatest weakness was it's thin armour, making it too vulnerable to advance with the leading infantry company. Lacking close fire-support, Canadian infantry got mauled by German counter-attacks in Normandy.

The Ram's large diameter turret pre-dated the Sherman's. Ram's primary contribution was to goad Americans into installing a large turret and 75 mm gun on Sherman's.

POD

What more could MLW do to improve on the basic Ram/M-4 Sherman design to better support Canadian infantry in Normandy?
To maintain chassis reliability we must keep the gross weight near the original 30 tons.

Step 1 - flip the Wright-Continental radial-engine on it's nose, so that it lays lower in the hull.
Step 2 - design a 90-degree gear box to replace the bell-housing and lay the drive shaft on the hull floor. This will allow the turret basket floor to lay 18 to 24 inches lower in the hull
Step 3 - Re-slope the glacier plate and hull bustles. Yes, this will reduce ammo storage space in the side hull, but weren't ammo fires a leading cause of Sherman's being abandoned. We might have to eliminate the bow gunner to make room for ammo (ala Sherman Firefly). Transfer the weight savings to thicken the glacis plate, for the same gross weight.
Step 4 - MLW cast a new, longer turret. Slope the turret front and sides like a Walker Bulldog. Only leave a tiny slot for the main gun to protrude. Cast the turret bustle long enough to accommodate radios and counter-balance the weight of a 17-pounder gun.
Step 5 - Counter Panzerfausts by hanging a variety of sheet metal tool boxes around the hull and turret. Install track shrouds, but make them easy to remove when going gets muddy. Weld bolts to the glacier plate to facilitate carrying spare track links.
Step 6 - After summer 1942, install 17 - pounder guns.
Step 7 - Assign CARDE to develop HE ammo for 17-pounder. CARDE might need to lower HE muzzle-velocity to around 2,000 GPS to allow a sufficient amount of explosive.
Step 8 - Encourage troops to run Ram III into the ground and take lessons- learned to build Ram IV even tougher.

In summary, Ram III is a smaller (lower) target than Sherman with a higher velocity gun, but the same reliable running gear.

[FONT=Arial,Helvetica,Monaco]Ram 3.7 in Anti-aircarft gun[/FONT]




[FONT=Arial,Helvetica,Monaco]Ram 3-in Self-propelled gun[/FONT]

Yes, I have both those photos in "Secret Weapons of the Canadian Army."
An open gun is too vulnerable to closely support infantry.

M-10 was not issued to Canadian Armoured Corps. Even when retrofitted with 17-pounder gun, it'd open-topped turret made M-10 too vulnerable for close-support. The other problem with the M-10 turret was it's poor balance. M-10 turret's centre of gravity was too far forward requiring massive ballast and powered traverse. Commonwealth tankers preferred Sherman Fireflys over M-10s.

Remember that the original goal of this thread was to design an infantry-support tank BETTER than Sherman Firefly.

If you reduce the depth of Ram III hull by 18 to 24 inches, how much will that reduce empty weight?
How can that weight be best re-applied to improve protection?
Greater slope to glacis plate?
Thicker glacis plate?
Greater slope to hull sides?
Greater slope to Langley?
Thicker gun mantlet?
Sloped turret sides?
Would improved armour enable Ram III to stand up to German long-barrelled 75 mm tank gun? ..... 88 mm?

I like the idea of getting Ford to build its V8 tank engine in Canada before the US joins the war. And use THAT for the Rams. Then, as they get heavier, with bigger guns and more armour, upgrade to the original V12 version (that the V8 was cut down from).

What about go for even lower profile and design a Sturmgeschutz-RAM?

Depending on intended use and time:
* 17 pounder
* US 90mm M3
* 25 pounder

Convert the weight save by the lowered hull height and turret weight and increase the thickness of the glacis (as suggested above). Go with the also mentioned side skirts.

riggerrob said:

Step 1 - flip the Wright-Continental radial-engine on it's nose, so that it lays lower in the hull.
Step 2 - design a 90-degree gear box to replace the bell-housing and lay the drive shaft on the hull floor. This will allow the turret basket floor to lay 18 to 24 inches lower in the hull

Click to expand...

The R-975 engine is 45" wide and 43" long. Laying the engine down onto a right-angle gear box of a certain thickness will add to the 43" in length, which is now height. It will also be a very tricky installation to torque down the joining hardware without sufficient clearance, also required for the passage of cooling air, separated from the hot air effluent. What you really want is a custom-made off-set gearbox on an up-right engine, which will only add cost, weight and complexity if it's done right.

Driftless said:

What about go for even lower profile and design a Sturmgeschutz-RAM?

Depending on intended use and time:
* 17 pounder
* US 90mm M3
* 25 pounder

Convert the weight save by the lowered hull height and turret weight and increase the thickness of the glacis (as suggested above). Go with the also mentioned side skirts.

Click to expand...

Or what about skipping straight to the Sexton? Roughly around the same time, the UK was looking at providing mobile artillery support and developed the Bishop. Perhaps in TTL they manage to convince the Canadians to produce a variant of the M3 that mounts a 25 pounder?

Just Leo said:

The R-975 engine is 45" wide and 43" long. Laying the engine down onto a right-angle gear box of a certain thickness will add to the 43" in length, which is now height. It will also be a very tricky installation to torque down the joining hardware without sufficient clearance, also required for the passage of cooling air, separated from the hot air effluent. What you really want is a custom-made off-set gearbox on an up-right engine, which will only add cost, weight and complexity if it's done right.

Click to expand...

.................................
Out of that 43 inch length, the first quarter is the bell housing propeller reduction gears. The last third is accessories: carburetor, magnetos, pumps, etc some of those accessories could be relocated to reduce length. Also consider that coaxial
Cooling fan is not mandatory. Also think about routing cooling air down triangular corner ducts, bending it at floor level, then blowing heated air up through a central cooling duct.
There are a dozen different ways to route engine accessories if you have the imagination.
Can we at least agree that laying the drive shaft on the hull floor would make Ram III a smaller target?

riggerrob said:

.................................
Out of that 43 inch length, the first quarter is the bell housing propeller reduction gears. The last third is accessories: carburetor, magnetos, pumps, etc some of those accessories could be relocated to reduce length. Also consider that coaxial
Cooling fan is not mandatory. Also think about routing cooling air down triangular corner ducts, bending it at floor level, then blowing heated air up through a central cooling duct.
There are a dozen different ways to route engine accessories if you have the imagination.
Can we at least agree that laying the drive shaft on the hull floor would make Ram III a smaller target?

Click to expand...

We can agree that the drive shaft routing was an impediment in the tank design. Your solution doesn't answer several critical questions, assuming the fiddly-bits will take care of themselves. The simple solution is to use an engine designed to use a lower output shaft. The Wright engine is the wrong engine. Several attempts to design ducted cooling systems have failed due to overheating. Engine accessories may be ignored in the imagination, but exist in real life. I was wondering how the lay-down radial's lubrication system would work. Have you given it any thought?

....... I was wondering how the lay-down radial's lubrication system would work. Have you given it any thought?[/QUOTE]

..................................................

Lubrication systems worked well in the laid-down radial engines of several 1940s and 1950s vintage helicopters. They also lubricated well in the 45 degree angle mounting in Sikorsky's early transport helicopters.
My primary motivation -to retain the Wright/Continental radial engine - was to smooth production. That engine was obsolete for fighting planes by 1940, but had the great power-to-weight ratio needed for tanks.

We can agree that a V-8, V-10 or V-12 engine would be easier to integrate with a floor-level drive shaft. The challenge remains to start with an engine that had been perfected by 1940 and was not valuable for some other vehicle.

Continuing in my line of dumb questions:

I realize in the early WW2 time frame, everyone was scrambling to find a comparatively compact engine with a ton of horsepower, so it could be crammed into any tank or other tracked vehicle. Some were jumped up truck engines, some were aircraft engines, and some were diesel punk bolted together conglomeration of what-nots. Some options worked, some didn't.

Had anyone ever tried a "boxer" style opposed cylinder engine in one of these vehicles? Or didn't such an animal exist with sufficient horsepower for the requirement? I would think that format could fit the basic engine compartment layout.

Or did evolution just take it's course, and "conventional" inline or v-type engines become dominant, as much because of the knowledge & experience base? Is there something inherently more usable with the conventional, water cooled inline/v-engines for the use of tossing around several compacted tons of steel?

Driftless said:

Continuing in my line of dumb questions:

I realize in the early WW2 time frame, everyone was scrambling to find a comparatively compact engine with a ton of horsepower, so it could be crammed into any tank or other tracked vehicle. Some were jumped up truck engines, some were aircraft engines, and some were diesel punk bolted together conglomeration of what-nots. Some options worked, some didn't.

Had anyone ever tried a "boxer" style opposed cylinder engine in one of these vehicles? Or didn't such an animal exist with sufficient horsepower for the requirement? I would think that format could fit the basic engine compartment layout.

Or did evolution just take it's course, and "conventional" inline or v-type engines become dominant, as much because of the knowledge & experience base? Is there something inherently more usable with the conventional, water cooled inline/v-engines for the use of tossing around several compactyed tons of steel?

Click to expand...

..............................

Most WW2 tank engines were minor modifications of existing bus (Churchill) or truck or aircraft (Sherman) engines.
The French did develop a beautiful flat-8, horizontally-opposed engine for their Panhard Engin Blinde' de Recconainsance (8-wheeled) heavy armoured car. That engine was assembled with 8 air-cooled cylinders " liberated " from Citroen 2-CV deux cheveux (2 horsepower) cars. If the VW Beetle was "Hitler's revenge, then the 2CV was "DeGaul's revenge," a cute, lightweight, inexpensive car that was quite useless in a crash.
That thin pancake engine fit neatly under the EBR's turret floor.
Because of it's pancake engine, the EBR was the lowest and sleekest of 1940s-vintage armoured cars. The EBR's greatest disadvantage was needing a crane - to lift off the turret - before you could do major repairs to the engine.

Purists will remind us that EBR was not manufactured until after WW2, but the French did build a couple of EBR prototypes before WW2, when those silly Germans interfered with R&D.

Driftless said:

What about go for even lower profile and design a Sturmgeschutz-RAM?

Depending on intended use and time:
* 17 pounder
* US 90mm M3
* 25 pounder

Convert the weight save by the lowered hull height and turret weight and increase the thickness of the glacis (as suggested above). Go with the also mentioned side skirts.

Click to expand...

..................................................................

Sturmgeschutz Ram prototype was built at CARDE, but it was not exactly official. CARDE gunners were test-firing an American 90 mm gun from an M-3.5 hull during the coldest days of winter. To cut the bitting wind, they hung sheets of plywood on the hull.
Hah!
Hah!
Got to love those redneck engineers!

riggerrob said:

That engine was assembled with 8 air-cooled cylinders " liberated " from Citroen 2-CV deux cheveux (2 horsepower) cars.

Click to expand...

12 cylinders, I believe. Less than 22cm in height but only six litres displacement. Good for a 13 ton armoured car but scale it up three times or so and it's will be a big odd-shaped lump to fit into a tank.

Trying to find decent engines for ww2 tanks is heart-breaking. The best bets IMO are the aforementioned Ford GA, the soviet diesels, any spare Allison or Merlin engines that fail air-rating, or getting Detroit Diesel to cook up a V-configured version of the 71 series. Beyond that maybe Buda, Hercules, Hall-Scott or Continental could do something in a V or flat configuration. But even tank transporters in WW2 were running straight-six engines...

Driftless said:

What about go for even lower profile and design a Sturmgeschutz-RAM?

Depending on intended use and time:
* 17 pounder
* US 90mm M3
* 25 pounder

Convert the weight save by the lowered hull height and turret weight and increase the thickness of the glacis (as suggested above). Go with the also mentioned side skirts.

Click to expand...

..........................................................................

According to "Secret Weapons of the Canadian Army" they briefly toyed with the idea of mounting a 17-pounder in a Sexton but discarded the notion when they figured out how big and bulky it would be.

Am I allowed to spin off my own thread to invent a variety of AFVs based on Valentine chassis?

By the time the first 17-pounders were available for field trials (summer 1942) Valentine production was slowing in Canadian factories. By mid-1942 all Canadian-built Valentines were going straight to the USSR under Lend-Lease. Russians valued Valentines as reliable recce tanks.

WI Canadian factories had started building Valentine Archers in late 1942?

WI Canadian factories revived the Bishop ASAP gun?
The key departure is that the Bishop II is based on an Archer hull so that the 25-pounder gun fires aft, over the engine compartment? A wide casement allows the gun to travers 90 degrees while a recoil spade is hinged to the glacis plate.

WI de-frocked Bishop IIs are pressed into service as ammo carriers and APCs?

Normandy, summer 1944: A harried CAN LOAN Royal Canadian Electrical Mechanical Engineer is rushing back to the front-line with a valuable box of Valentine clutches scrounged from ..... "you would be wise not to ask" .... When he passes a convoy of Bishop II ammo carriers. His professional eye first notes black smoke belching out of the exhausts, then shiny slack tracks. As he pulls ahead of the convoy he casually notices saggy ammo cranes and shiny, saggy recoil spades.
"Which way sir?" Demands the driver.
The captain fumbles for his map and yells "Left corporal! Left just before the bridge!"
After following the river for a couple of miles, they notice loose gravel strewn towards a farm gate.
"Corporal! Please pull over to the right!"
They park along a hedgerow and walk over to a battery of Bishop IIs. Soldiers with shovels are putting the final touches on gun pits. Oddly, SP guns are romping around a field laced with half-dug trenches.
"Corporal see if you can scare up a spot of tea while I chat up the battery officer."
As he approached, the captain saw fresh, dark brown soil spilling off the front of the nearest ASAP gun.
"Can I help you sir?"
He turned to greet a haggard soldier. His haunted eyes sank deep amongst the dirty furrows of his face. He looked like he had neither washed nor shaved in the past couple of days.
"Yes private. Please lead me to your battery officer."
"I am the battery officer! Humpf!"
"But you don't look like an officer without epaulets or binoculars or pistol. Appearances are everything my good sir. We must keep up appearances for the sake of the troops!"
"Appearances attract jerry bullets. Epaulets attract jerry snipers."
"But don't you need binoculars to do your job?"
"Sure" the rumpled Leftenant mumbled as he pulled a battered pair of binos half-way out of his dusty battle dress jacket. "But I try not to flash them around. Jerry is low on bullets, so I try not to look important."
"Well, what about a pistol to defend yourself?"
As he sneaks a pistol halfway out of his pants pocket "Not much use at these ranges. If looks like we might get too close, I grab a Sten gun, but MGs are my first choice." as he waves towards a Browning machine gun on top of a nearby Bishop.

"Harrumph! Enough about appearances! What the blazes is that Bishop doing over there?"
"Digging in ammo?"
"Digging in ammo?"
"Sir, do you see that convoy of ammo carriers coming over the hill?" replied the Lt.
"Yes, but what does that have to do with abusing Royal Artillery property by digging holes?"
"Captain, we have to dig-in that ammo .... get it below ground level .... before we can get any sleep. Most of my gunners have been on their feet for four days straight."
"But!"
"But jerry is short of ammo. So he likes to wait until we are almost finished digging in before he calls down counter-battery fire. Then we have to crash habour and dig-in somewhere else. Quite a bother old chap! By using the recoil spades to dig-in, we can be dug-in before sunset. With traditional shovels we would be lucky to finish digging-in by dawn. Jerry is not half as accurate during night shoots. Now if you will excuse me, I have to dig-in my fire control pit."
"But digging in the dirt is work for soldiers, not officers!"
"Maybe in a peacetime army sir! But as you can see, all my gunners are fully-employed digging-in the guns. Officers must lead by example." shrugged the Lt. as he un-strapped a shiny pick from the side of his Bren Carrier.
"But! But! Your regiment is burning through clutches five times faster than the Kangaroo regiment next door!"
"Better to burn through clutches than gunners."
"But! But! Where are we going to find more clutches?"
"Not my problem Captain. Now if you are so fond of tradition, may I suggest that you lead by example while you swing this shovel with the troops?"
said the Lt. as he hefted his own pick.

I had read that Japan developed a air-cooled diesel engine for tanks-would that work out if chosen?

I love the Ram Tank-I use it in GearKrieg campaigns.

There's the GM 4046 twin diesel @ 450hp, but it weighs over 5000lbs.


http://usautoindustryworldwartwo.com/General Motors/detroit-diesel.htm

Ram

The SOMUA S35 was a French tank built from 1936 until 1940 to equip the armoured divisions of the Cavalry. It was for its time a relatively agile medium-weight tank constructed from well-sloped, mainly cast, armour sections and was superior in armour and armament to both its French and foreign competitors. From the S35, SOMUA developed in 1937 the SAu40 self-propelled 75 mm gun. Its drivetrain featured an extra wheel to improve off-road capabilities, and the hull was wider. As the vehicle was apparently under-appreciated by the French, Canadian Tank Arsenal (utilizing Canadian National Railway's Montreal Locomotive Works) obtained a license to build the SAu40 in Canada as the "Aries" SPG in early 1939 and fitted it with the V12 Condor Major diesel engine, Synchromesh transmission, Bison track system and an OQF 75mm Mk.I gun fitted with a large muzzle brake to soften the recoil. Arming the Aries with the US made M1897 75mm gun, designated 75mm Mk.I in British use, rather than the British 3-in howitzer provided a close support, anti-personnel capability while allowing the use of French designed 75mm APDS (75mm/57mm) ammunition and the US M66 HEAT round in the anti-tank role as these became available. The M66 HEAT could penetrate about 91 mm of homogeneous armor at 0 degrees within range. From this CTA also developed the "Ram" tank in 1940, initially fitted with the same turret and gun used on the A12 Matilda. However, in Nov 1941 this was replaced with a new turret designed by L.E. Carr of the Canadian Interdepartmental Tank Committee to be fitted with a 75mm gun or, by May 1942, a 6-pdr (57mm) AT gun. At the same time the suspension and track system were also replaced with that developed for the M3 tank due to its superior ease of production and maintenance. The 25-pdr armed "Sexton I" SPG was also developed from this chassis (the similar Sexton II was on a Sherman type chassis). The "Aries" was refitted with the M2A1 105mm howitzer for use against fortifications and, using the M67 HEAT round, armoured vehicles. The M67 HEAT could penetrate about 102 mm of homogeneous armor at 0 degrees within range. The "Ram" was never used in combat in tank form, being replaced in service by the M4A5 "Grizzly"prior to operations in Normandy, but for crew training in Canada and Great Britain up to mid 1944. The 105mm "Aries" and 25-pdr "Sexton I" saw considerable active service in North West Europe along side Ram Command tanks, Badger flame tanks, Wallaby munitions carriers and Kangaroo APC's. All Ram based AFV's in the UK and Europe were presented to the Royal Netherlands Army between 1945-47 and continued in use until replaced by Centurion tanks in 1952.
http://panzercentral.com/forum/viewtopic.php?f=93&t=43002&start=0

Currently working on a 3D model of the Ram although it may take a few days before there is anything worthwhile showing... After that I'd be happy to make any suggested mods to it so you can have an all round view of the thing.