Here's some background courtesy of Wikipedia, plus some images I've picked up off the web from a variety of sources including the Imperial War Museum
Overview
The Comet tank or Tank, Cruiser, Comet I (A34) was a British cruiser tank that first saw use near the end of World War II during the Invasion of Germany. It was developed from the earlier Cromwell tank and mounted the new 17 pdr High Velocity (HV) (3 inch; 76.2 mm – sometimes referred to as "77 mm") gun, in a lower profile, partly-cast turret. This gun was effective against late-war German tanks, including the Panther at medium range, and the Tiger. The tank was widely respected as one of the best British tanks of the war, and continued in service afterwards.
The Comet, which was a development of the Cromwell, rendered the Challenger obsolete, and led to the development of the Centurion tank. When firing APDS rounds, the 77 mm HV was superior in armour penetration capability to the 75 mm KwK 42 gun of the equivalent Axis tank, the Panther (which did not use APDS ammunition). The Comet saw action in the closing stages of World War II and remained in British service until 1958. In some cases, Comets sold to other countries continued to operate into the 1980s.
Background
Combat experience against the Germans in the Western Desert Campaign demonstrated to the British many shortcomings with their cruiser tanks. Hence a request was made in 1941 for a new heavy cruiser tank that could achieve battle superiority over German models. For reasons of economy and efficiency, it had to use as many components as possible from the current A15 Mk VI Crusader tank.
The initial designs for the new Cromwell tank evolved into the A24 Mk VII Cavalier tank and the A27L Mk VIII Centaur tank, both powered by the Nuffield Liberty. Design progressed through the Mk VII (A27M) Cromwell, a third parallel development to the Cavalier and Centaur, sharing many of the same characteristics.
Under the newer A27M specification, Cromwell integrated a number of advanced features. The Meteor engine proved to be very reliable and gave the tank good mobility but some problems appeared based on the vehicle's shared heritage and significant jump in engine power. The tank was prone to throwing its tracks if track tension was not maintained properly or if it turned at too high a speed or too sharply. There were also some problems with suspension breakage, partly due to the Cromwell's high speed and it ran through a number of design changes as a result.
The biggest complaint was related to firepower; the Cromwell had originally been designed to carry the 57 mm Ordnance QF 6-pounder, also retrofitted to the Crusader tanks. In combat, these were found to be useful against other tanks but lacking any reasonable high explosive load they were ineffective against anti-tank guns or static emplacements. Prior to the Cromwell entering combat service, the Ordnance QF 75 mm was introduced which equipped the majority of Cromwells, an adapted version of the 6-pounder firing shells from the US 75 mm gun from the Sherman. This offered somewhat lower anti-tank performance than the 6-pounder but its much larger shell provided an effective high explosive load.
Several attempts had been made to further improve firepower by fitting a more powerful gun. In parallel with development of the Cromwell and QF 75 mm gun, a new Vickers High Velocity 75 mm tank gun had been designed but this proved too large for the Cromwell turret ring and left a shortage in offensive anti-tank capability. A prior requirement for a 17-pounder armed tank led to development of the A30 Mk VIII Challenger. Based on the Cromwell, the hull had to be lengthened and a much larger turret set on top to allow a second loader for the 17-pounder, a requirement of the older specification believed necessary for the larger ammunition. The very high turret of the Challenger was considered a liability and this led to experiments with the similar A30 Avenger version, an anti-tank version with an open-top turret.
Conversion of Sherman tanks to the Sherman Firefly (a Sherman tank fitted with the 17-pounder gun) was significantly faster than Challenger production and driven by operational needs of the Normandy invasion, production of Challenger was dropped. Fireflies (and the limited number of Challengers) provided additional firepower to Cromwell and Sherman armed troops. One Firefly would be issued to each troop of Cromwells (giving three Cromwells and one Sherman Firefly). Problems were encountered due to the different maintenance requirements and associated supply complication of two tank models, as well as the performance difference between Cromwell and Sherman and the Sherman's silhouette, even larger than the Challenger. The large size and obvious difference of both Challenger and Firefly made them a priority target for Axis forces.
Recognising that a common low profile vehicle was required to replace the mixed fleet of Cromwell, Challenger and Firefly tanks, a new specification of tank was created. This removed the Challenger's need for a second loader and mounted the newer Vickers High Velocity weapon intended for the Cromwell.
Tank, Cruiser, Comet l (A34)
With the A34 (the General Staff specification), later named Comet, the tank designers opted to correct some of the Cromwell's flaws in armament, track design and suspension while building upon its strengths of low height, high speed and mobility. This replaced the need for the Challenger and Firefly and acted upon the experiences gained through design and early deployment of the Cromwell.
Originally, it had been expected that the Cromwell would use the "High Velocity 75 mm" gun designed by Vickers but it would not fit into the turret. Development of the gun continued and as work commenced on the Comet, the gun design evolved into the 17 pdr HV (High Velocity). The gun now used the same calibre (76.2 mm) projectile as the 17-pounder but the cartridge case was from the older QF 3 inch 20 cwt anti-aircraft gun loaded to higher pressures. The resulting round was different from 17-pounder ammunition, being shorter, more compact and more easily stored and handled within the tank.
The 17 pdr HV was a shortened 17-pounder. This made it possible to mount the gun on a smaller turret ring. The gun was still capable against opponents and firing APDS rounds, more accurate and consistent than APDS from the 17-pounder and 6-pounder, which were inaccurate over 700m and often ricocheted. The Challenger turret had been so large to allow space for two loaders.
Several other improvements were made and many Cromwell design revisions were incorporated, such as safety hatches for the driver and hull gunner. The hull was fully welded as standard and armour was increased, ranging from 32 mm to 74 mm on the hull, while the turret was from 57 to 102 mm.
A new lower-profile welded turret was created using a cast gun mantlet for the 77 mm. The turret was electrically traversed (a design feature taken from the Churchill tank), with a generator powered by the main engine rather than the hydraulic system of the Cromwell. Ammunition for the 17 mm gun was stored in armoured bins.
The Comet's suspension was strengthened, and track return rollers were added. As with later Cromwells, the Comet tank's top speed was limited from the Cromwell's 40+ mph to a slower, but respectable 32 mph (51 km/h). This change preserved the lifespan of suspension and engine components and reduced track wear.
Similar to later Churchills, the Comet benefited from lessons learned in the co-operation of tanks with infantry. It was fitted as standard with two radio sets: a Wireless Set No. 19, for communication with the regiment and the troop, and a No. 38 Wireless for communication with infantry units. Like many British tanks, it also had a telephone handset mounted on the rear so that accompanying infantry could talk to the crew.
Production
Comet tanks were built by a number of British firms led by Leyland, including English Electric, John Fowler & Co., and Metro-Cammell
The mild steel prototype was ready in February 1944 and entered trials. Concerns about the hull gunner and belly armour were put to one side to avoid redesign, but there was still sufficient delay caused by minor modifications and changes. Production models did not commence delivery until September 1944. The Comet was intended to be in service by December 1944, but crew training was delayed by the German Ardennes Offensive. By the end of the war, 1,200 had been produced.
World War II Service History
The British 11th Armoured Division was the first formation to receive the new tanks, with deliveries commencing in December 1944 and the 29th Armoured Brigade, then equipped with Shermans, was withdrawn from fighting in the southern Netherlands early in the same month for re-equipping. After arriving in Brussels and preparing to hand in their Shermans the Ardennes Offensive commenced, and the brigade was forced to hastily take back its Shermans in order to take part in the countering of the German attack. The unit returned to the Brussels area in the middle of January 1945 three weeks later and finally paid-off its Shermans in exchange for Comets. The 11th Armoured would be the only division to be completely refitted with the Comet by the end of the war. The Comet saw combat and 26 were destroyed but due to its late arrival in the war in north west Europe, it did not participate in big battles. The Comet was involved in the crossing of the Rhine and the later Berlin Victory Parade in July 1945. The Comet's maximum speed of 32 miles per hour (51 km/h) was greatly exploited on the German Autobahn (motorways).
There's more information at the excellent Tanks Encyclopaedia: here
Onto the kit which has been lurking in my stash for a little while
Here are the sprue frames - not a huge part count compared to some armour kits
In the following shot there are two each of the wheels sprue & flexible track
There were some aftermarket additions included in the kit I picked up: wheels, tracks, barrel & mantlet but not sure how much of this I'll use yet
And finally the instruction book - some of which has instruction annotation only in (I think) Chinese... which may prove interesting
I've got something to finish off on the bench at the moment but hopefully I'll be able to get started soon.
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