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Shorter isn't a problem, if you don't mine a hump in the backIf somebody wants a shorter engine than the Liberty it is simple.
Turned out to be surprisingly reliable, MTBF of 240 hours, with the GAA V8 of 255. the Radial was 218Five cast iron, flat head 6 cylinder engines ganged together. You had an engine factory that was spitting out the car engines at thousands per week vs a set of drawings and a prototype?
Yes the Ford was better engine, but it arrived late.
My grandfather had a Nuffield tractor. He might have acquired it in the late 1950'ies or 1960'ies, I don't really know. But it was in regular use until the late 1980'ies. From what I understand he generally liked it, it was reliable and easy to work on, and did what it was supposed to. I think it's still standing in a shed on my aunt's property, I'm sure it'd still be perfectly usable after some maintenance.Makes we wonder if Nuffield's Engineers were secretly in pay of the Germans at times.
I guess in retrospect for tanks the lesson is to design the engine and transmission as an easily replaceable power pack, anything beyond some basic routine maintenance and you lift out the engine + transmission with a crane, slot in a new power pack and the tank is ready to go while the maintenance crews have time and plenty of space for accessing the engine for maintenance.Bad head gasket, You have to pull the engine out of the car to have enough room to pull a cylinder head
well, they have been doing that since the 60s and were working on the basic idea in 50s.I guess in retrospect for tanks the lesson is to design the engine and transmission as an easily replaceable power pack, anything beyond some basic routine maintenance and you lift out the engine + transmission with a crane, slot in a new power pack and the tank is ready to go while the maintenance crews have time and plenty of space for accessing the engine for maintenance.
From pre-war days British Army units were provided with REME Light Aid Detachments. Amongst the vehicles they had were thesewell, they have been doing that since the 60s and were working on the basic idea in 50s.
In the late 30s most countries were lucky the army got actual tanks that bigger than 5 tons and the idea even buying trucks with cranes that would lift even one ton would be seen as laughable. See photos aircraft engine swaps with tripods made of long wooden poles and block and tackles.
They may have had crane trucks, they just didn't have many. Recovery vehicles (jib booms and winches) didn't show up for the first few years.
The 3M-2500 was not related to the Liberty. It was substantially larger and would be more difficult to fit into a tank. Note the Packard weight includes the reversing gearbox.I wonder how Packard's 3M-2500 (marine version of the above-mentioned Liberty) would have worked in an AFV?
Thank you but vehicles such as these would be very scarce in 1938-40. Things better quickly and the British were using some theseFrom pre-war days British Army units were provided with REME Light Aid Detachments. Amongst the vehicles they had were these
Good point about the multi-bank engine.The 30 cylinder Chrysler was not designed to be the ultimate engine. It was designed to be something at could be put into tanks very quickly.
View attachment 782993
Five cast iron, flat head 6 cylinder engines ganged together. You had an engine factory that was spitting out the car engines at thousands per week vs a set of drawings and a prototype?
Yes the Ford was better engine, but it arrived late.
They built 109 M3 Grants with the Chrysler engine.
In 1941/42 when they were trying to figure out how to make wooden airplanes in case there was a shortage of aluminum, ordering thousands of aluminum tank engines might not have been high on the priority list. Took a while but it turns out the aluminum shortage didn't exist.
In WW II both the US and the Germans usually separated the engine and transmission and put them at opposite ends of the tank making the Power Pack idea rather moot
But just how many vehicles do you think the British Army had in 1939?Thank you but vehicles such as these would be very scarce in 1938-40.
The need for the Armoured Recovery Vehicle arose out of the discovery of a need from the Western Desert campaigns to recover tanks from the battlefield while under fire. From the later part of the REME article I posted before:-Things better quickly and the British were using some these View attachment 783363
by mid war. There were a few Covenanter versions for training.
The rapid escalation from 15-16 ton tanks (and 6 ton light tanks) to 21-30 ton tanks left several nations scrambling for recovery and repair vehicles.
Lifting out power units (engines, transmissions, final drives) as complete units took awhile to figure out and required more equipment than taking the units out in pieces (engine only, transmission only, etc) although taking much less time to accomplish. Modern (1970s and on?) armies often had two different ARVs. One for the MBTs and one for the personnel carriers/infantry fighting vehicles with the appropriate booms/cranes to handle the different sized components.
Tanks often managed to breakdown in places that even 4 X 6 and 6 X 6 wheeled vehicles had trouble getting to.
In WW II both the US and the Germans usually separated the engine and transmission and put them at opposite ends of the tank making the Power Pack idea rather moot. removing the engine a cooling system was possible. British and Soviets kept the engines and transmissions together although that is somewhat debatable.
View attachment 783364
Not the most compact arrangement although have room to work on things without needing heavy machinery might have been seen as a plus at the time.
Making a combined package does limit the number of lifting devices that will work.
What people thought were good ideas in 1939 may not have been thought good ideas in 1946
I always thought this was a dumb move. Put the drive sprocket, engine and transmission at the rear. Design your track, wheels and CG to discourage the track coming off. Or, put everything at the front like the postwar Merkava.In WW II both the US and the Germans usually separated the engine and transmission and put them at opposite ends of the tank making the Power Pack idea rather moot.
The 'transmission' (includes steering, brakes, final drives and associated clutches) often was heavier than the engine. Helped balance the tank out vs all the weight on one end. even out the track loading and evened out the bogie wear. See problems with German MK IV tanks and tank destroyers using MK IV chassis. different reason but the heavier armor and larger guns in 1944-45 tore up the front bogies wheels so bad they stopped using rubber tires on the first pair of wheels, or they used wheels with steel tires on rubber spacers on steel hubs.I always thought this was a dumb move. Put the drive sprocket, engine and transmission at the rear. Design your track, wheels and CG to discourage the track coming off. Or, put everything at the front like the postwar Merkava.
A front drive sprocket is better for keeping the tracks on when the tension slacks, such as going over rough ground or when turning.I always thought this was a dumb move. Put the drive sprocket, engine and transmission at the rear. Design your track, wheels and CG to discourage the track coming off. Or, put everything at the front like the postwar Merkava.
For the Israelis, with their experience of using tanks in various ME conflicts, putting the engine & transmission at the front was about increasing the protection and survivability for the crew. With the crew compartment at the rear, a large door could be fitted easing escape of the crew or allowing the compartment to be used for other purposes with little modification e.g. carriage of troops or stretchers.I always thought this was a dumb move. Put the drive sprocket, engine and transmission at the rear. Design your track, wheels and CG to discourage the track coming off. Or, put everything at the front like the postwar Merkava.
A front drive sprocket is better for keeping the tracks on when the tension slacks, such as going over rough ground or when turning.
It's also easier to make and control the Steering Clutch/Brakes and the transmission clutches and gears when it's all manual and being done with pushrods. Long linkages are a pain to keep adjusted, and the long rods will flex.
For the Israelis, with their experience of using tanks in various ME conflicts, putting the engine & transmission at the front was about increasing the protection and survivability for the crew. With the crew compartment at the rear, a large door could be fitted easing escape of the crew or allowing the compartment to be used for other purposes with little modification e.g. carriage of troops or stretchers.
The 'transmission' (includes steering, brakes, final drives and associated clutches) often was heavier than the engine. Helped balance the tank out vs all the weight on one end. even out the track loading and evened out the bogie wear.
See problems with German MK IV tanks and tank destroyers using MK IV chassis. different reason but the heavier armor and larger guns in 1944-45 tore up the front bogies wheels so bad they stopped using rubber tires on the first pair of wheels, or they used wheels with steel tires on rubber spacers on steel hubs.
A lot depends on what you have to work with. British put everything in one end. But they used (mostly) large engines with few gears but good steering systems and there were a number of steering systems.