As I understand it, the Vanguard was a planned tank (or is it more appropriate to call it a variant?) based on the Valentine, with the individual wheel suspension of the Valiant. But - per a discussion here previously - apparently the Soviets wanted to keep receiving Valentines, so the plan was scrapped. Would the hull and turret of the Vanguard have been the same as the Valentine's? Were any Vanguard prototypes built?
I had a glance at this link: http://www.tankmuseum.org/museum-online/vehicles/object-e1952-39 Because: "LABEL: By 1942, the British and Americans shared a requirement for an assault tank, which Vickers proposed to fulfil with a better armoured version of the Valentine infantry tank. By September 1942, Vickers proposed to deliver Valiant Is with an uprated version of the Valentine’s engine, followed by Valiant IIs with prospective Rolls-Royce Meteorite engines. Rolls-Royce designed this vehicle from January 1943, supported by Ruston & Hornsby from March 1943, with driving controls that were too dangerous to use, driver hatches that fouled the gun, and a tail with so little ground clearance that it caught on almost any rise." "Rolls-Royce planned delivery of three different pilots: Valiant I in 1943, Valiant II a few months later, and a larger and better armoured Heavy Valiant in 1944. The Heavy Valiant seems to have been known, by various confused authorities, as Valiant Mark III and Vanguard. Belper planned to adapt the Valiant for the US T1/M6 heavy tank’s running gear, which Belper had selected for the Heavy Cromwell. Belper ignored the Tank Board’s requirement for a version with 17-pounder gun, and specified a 57mm six-pounder gun, with allowance for a 75mm gun or a 95mm howitzer, each with coaxial machine-gun. For no good reason, Belper proposed an alternative armament of twin Oerlikon cannons with coaxial machine-gun, or multiple machine-guns, possibly combined with a 20 mm Oerlikon cannon." And... "THIS VEHICLE: is the only known Valiant. It was produced, late in 1943 or early 1944 by Ruston & Hornsby. This survives with a 75 mm gun, although possibly the 75 mm was a retrospective replacement for a 57 mm gun. No report of the first trial survives, probably because it could not proceed safely. Vision through the periscopes was limited to 10 yards ahead. When changing down from fifth gear, the gear change lever came back so violently, with so little space between it and the steering lever to the right of the driver’s knees that the driver might break his wrist in trying to operate it. The footbrake pedal was positioned such that the driver could depress it with only his heel, where it could become trapped between the pedal and the footplate. The driver was forced to sit in a crouched position that was uncomfortable and liable to injury by contact with the rear edge of the escape hatch. The rear of the hull offered a ground clearance of only 8.75 inches, and actually projected beyond the tracks, so the tank grounded on almost any rise. In May 1945, Ruston & Hornsby returned Valiant for trials of the suspension only, for which no reports could be found. Probably somebody at Vickers or Ruston & Hornsby had persuaded somebody at the Ministry of Supply that the suspension had been neglected, but the brief trial of May 1945 rediscovered the dangers, and the trial was abandoned after 13 miles. The School of Tank Technology retained the Valiant for demonstrating to students how not to design a tank, before transferring it to the Tank Museum."
All the blessed Fletcher has on Vanguard in 'The Universal Tank' (from which you may have gleaned what you have, but still worth a read.) Section on late-Mark Valentines, c. December '43 "In the meantime another replacement was being developed under the name of Vanguard. That it was not a dramatic development is clear from the fact some contemporary reports speak of the Valentine-Vanguard as if it were the same thing. Surviving details are few, although it is specified as weighing 16.5 tons against 17 tons for a late model Valentine. It was intended to carry a crew of three, a 6pdr & a Besa MG, at a speed at least 8mph faster than a Valentine. A pilot model is said to have been tested at some unspecified date in 1943 & these trials apparently revealed that the suspension was unsuitable, despite the fact that this appears to have been unchanged from the Valentine, beyond having equal-sized wheels. Vanguard was not proceeded with, due to the termination of the Valentine programme, although some parts for it were incorporated into the Archer SP Anti-Tank gun, and this may provide a clue to the Vanguard's appearance." Having a dig in a few other places, (Is it not mentioned in 'Into the Vally'? - starting there) but have a feeling Fletcher might be it. The name does not ring many bells.
I did not find a mention of it when looking through Into the Vally. The material I was looking at was in an archival file that Don Juan sent me Details that I found to follow.
In particular there are 3 "Vehicle Data Schedule" sheets here for Vanguard I, Vanguard II, and Vanguard III, dated 1943/01/30, which seem to differ primarily in engine. From their top speeds I would venture a guess that these are not Valiants because they all exceed the Valiant speed, at least the one listed on Wikipedia. And the armour is similar to a Valentine, not Valiant. Vanguard I - Max speed 19.5 mph, engine General Motors 6-71.A. Max BHP 165 at 1900 RPM Vanguard II - Max speed 22.5 mph, engine General Motors 6-71.M. Max BHP 210 at 2100 RPM Vanguard III - Max speed 19.5 mph, engine AEC A.190 (Improved). Max BHp 177 at 2300 RPM All - Crew 3 Armour 60 front and rear, 20 top and floor. Vanguard III has 50mm of side armour while the others have 43. Armament 6 pdr + Besa or 75mm + Besa. Six independently sprung wheels per side. As you quoted Fletcher, VP, a development of the Valentine rather than a reinvention. I'm not sure what Fletcher meant about the suspension having been the same aside from equal-sized wheels. It sounds like he was thinking the tank had the Valentine bogies but with 3 equal-sized wheels per bogie instead of one large and two small.
Not so easy to Google 'Vickers Vanguard' is it, without being swamped by a rather better known flying thing. My father made wings for it... Errrm. Combed all my more obvious books. Nothing. This will possibly be one of those ones waiting for serendipitous chapter and verse to appear in an unrelated file etc. Still, as long as the query's sat here, people may find it.
This is cobblers. Basically what happened is that the Valiant was cancelled in early 1944, and there was no "first trial" because the prototype had not been completed. Then a year later the War Office and Ministry of Supply asked Ruston & Hornsby to submit the prototype for suspension tests. This was simply because it was an untried suspension type, and the WO/MoS were curious to see how it performed. It's pretty obvious that Ruston & Hornsby had no incentive whatsoever to provide a fully functioning vehicle, as there would be no production contract forthcoming, and the company would have been shifting to peacetime production. All they did was lash up the prototype so that it would just about run, and I strongly suspect that many of the faults with it were deliberate in order to get this burden off the company's back.
Here for anyone's amusement are the specs I mentioned for Vanguard I/II/III. Honestly I'm not sure why anyone bothered - wasn't it clear that the Valentine was effectively obsolete? Then again I should take a look at the production dates for the 6-pdr and 75mm Valentines. In 1943? I also note that in 1942 there was a planned Valiant II which was apparently (?) not at that time a Heavy Valiant but simply the same vehicle with a 400 hp engine. In a meeting on December 16, 1942 the design was withdrawn because... the engine would not fit in the space available. P4190933 by Seroster posted Mar 29, 2018 at 8:57 PM P4190934 by Seroster posted Mar 29, 2018 at 8:57 PM P4190935 by Seroster posted Mar 29, 2018 at 8:57 PM
In further ref. to the Valiant tank, I recently saw this, where it gets a brief mention, about 5.30 mins in :
