About British tank designs...

OTL Ram was based on M3 (Lee and Grant) suspension, but was the first in its class to mount 2-pounder or 6-pounder guns in a large turret. Post WW2, the Dutch installed 75mm QF guns in a batch of Rams.

OTL Montreal Locomotive Works did not have to bend armour plate because they could cast armour as big as an entire Ram hull.

OTL No Kangaroos were purpose-built in Canada. Instead, Kangaroos were converted by a Canadian field workshop in Normandy starting during the summer of 1944. Kangaroo workshops started by de-frocking a batch of M7 Priests that had “shot out” their 105 mm guns. Subsequent batches of Kangaroos were based on Ram, Sexton or Churchill hulls. All the Kangaroos unnecessarily exposed infantry by forcing them to climb up the sides of the vehicle. Few Kangaroos got side ladders. None had seats in the infantry compartment. Ram-based Kangaroo (artillery) ammo carriers were often called “Wallabies.”
OTL Post War the Canadian Army converted a batch of M4A2E8s into Kangaroos by removing turrets.

OTL The primary motivation for converting Kangaroo APCs was the horrendous losses suffered by Canadian infantry regiments. The Black Watch of Montreal suffered 350 percent casualties during WW2! If Prime Minister MacKenzie-King was forewarned about casualties creating the Conscription Crisis of 1944, he probably would have ordered Montreal Locomotive Works to start building APCs a year earlier.

ATL The next question involves which chassis purpose-built APCs would be based upon.
OTL Montreal Locomotive Works built Valentines, Rams, Sextons and a few M4 Grizzlies. So th choice narrows down to Valentine or M3 hulls.
ATL Purpose-built APCS would be preceded by (fictitious) Bishop 2 SP guns (Valentine chassis) or M12 SP 155mm guns (Sherman chassis.) American 155mm SP batteries were issued one M20 cargo/ammo carrier per gun. M12 and M20 were based on M4 chassis with the driver in the bow, but a mid-mounted engine that freed up the rear hull for ammo, crew or 155mm howitzer. The next step is building significant numbers of portees/ammo carriers to support those SP guns. Converting ammunition carriers to APCs would merely involve welding on more armour plate. The greatest advantage of converted M3/M4-based mmo carriers is the ability to load and unload through rear hatches, reducing the time infantry are exposed to enemy fire.
 
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OTL Montreal Locomotive Works built Valentines, Rams, Sextons and a few M4 Grizzlies. So th choice narrows down to Valentine or M3 hulls.[/QUOTE]

I would go for an Valentine hull, think about an Archer, without a gun but a layout like an AMX13 APC.
 
A good illustration of the big problem with Christie suspension. The springs, dampers and cranks take up so much room in an already narrow hull. If we can get rid of the Christie suspension and use bolt on bogies like the US VVSS, HVSS or British Horstman it will give the crew more elbow/leg room.
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Its also obvious how much work would be involved fixing it compared to the Horstman below on the cent which was all mounted externally and 'bolted' to the outside of the hull


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Horstmann style takes up just as much width as Christie style, its just easier for maintenance accessibility.
HVSS/VVSS doesn't take any useful width away from the hull as the entire unit is within the tracks but has poor performance.
 
Horstmann style takes up just as much width as Christie style, its just easier for maintenance accessibility.
HVSS/VVSS doesn't take any useful width away from the hull as the entire unit is within the tracks but has poor performance.

Your right the Horstmann bogie takes up more width than say a torsion bar system or the Sherman VVSS/HVSS system but it still takes up less hull space than Christie. Horstmann bogies allowed the Centurion and later Chieftain hull sides to be sloped though the opposite way to most sloped armour the hull was narrower at the bottom than at the top. On a Cent the bottom track run was well away from the hull side but the top track run was almost scraping the hull sides.
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The Vickers Independent had an Armstrong Siddeley air cooled 350 bhp V12. Whatever happened to that engine and could it have been used in later designs? Of course the OTL option chosen was the Liberty water cooled V12.

The Rolls Royce V12 Eagle or by 1932 the diesel Condor variant with 500bhp
 
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Natural progression from the Vickers mk2 medium. The Vickers Chariot. 500bhp Condor V12 diesel, mounted to the left of the driver, same 3 man turret with 47mm 3 pounder with three pairs of horstman twin boggies suspension as per Vickers light tank or Valentines suspension and keep rear exit door for s couple of ‘Private Pikes’ with tommy guns. Voila Merkava 1935 style.
 
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. ... Horstmann bogies allowed the Centurion and later Chieftain hull sides to be sloped though the opposite way to most sloped armour the hull was narrower at the bottom than at the top. On a Cent the bottom track run was well away from the hull side but the top track run was almost scraping the hull sides.

Good point. I forgot about the hull slope :).
 
The Rolls Royce V12 Eagle or by 1932 the diesel Condor variant with 500bhp

The Condor by mid 30s is getting old fashioned no better than a Liberty. I do like the thought of a diesel Kestrel or Buzzard. A diesel Kestrel should be about 300hp and a diesel Buzzard should be 500hp plus the Buzzard was about the same size as a Merlin give or take an inch or two
 
Yes, Sir Harry Ricardo, developed a Diesel variant of the Rolls Royce V12 Kestrel aero engine in the 1930's. IIRC it was as a test bed for a sleeve valve aero engine that became the still born Crecy of the 1940's. I have yet to find details of the engine out put but it was used to set a diesel land speed record apparently.
 

Glyndwr01

Banned
Yes, Sir Harry Ricardo, developed a Diesel variant of the Rolls Royce V12 Kestrel aero engine in the 1930's. IIRC it was as a test bed for a sleeve valve aero engine that became the still born Crecy of the 1940's. I have yet to find details of the engine out put but it was used to set a diesel land speed record apparently.

I put the link and info in an earlier post!
 
Yes, Sir Harry Ricardo, developed a Diesel variant of the Rolls Royce V12 Kestrel aero engine in the 1930's. IIRC it was as a test bed for a sleeve valve aero engine that became the still born Crecy of the 1940's. I have yet to find details of the engine out put but it was used to set a diesel land speed record apparently.


In 1930, one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine, Sir Harry Ricardo, developped a Diesel variant of the Rolls Royce V12 Kestrel aero engine. This engine helped the land speed record breaking car ‘Flying Spray’ (f.k.a. Speed of the Wind) set a new diesel speed record at Bonneville Salt Flats, 159 mph, a record that would stand until 1950. Www.prewarcar.com
 
My Point was that This was an Experimental engine not a production design. Rather like the RR- R type Snyder engine (Also beloved of record breakers) which whilst of the same dimensions of the later Griffon engine was not directly developed into a production engine.
 
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