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-----Original Message-----
From: LEEnCALIF@aol.com <LEEnCALIF@aol.com>
To: Military Vehicles List <mil-veh@uller.skylee.com>
Date: 27 March 2000 02:54
Subject: [MV] Best tank of it's time...
Interesting. . . . . . .
>Response to "M-60 only a stop gap tank and that the Leopard is top quality..."
>
>.....I was talking only about a limit period of time so we could make a fair
>comparison. 1953-1973. Also I did place the Leopard as #3 on my list of all
>time best tanks for it's day, so I couldn't be that far off base. lol
>
There are some rumblings about Leopard, it would seem production ones didn't
exactly perform like the prototype demonstrators and no one was, allegedly,
clearly informed that these demo models were made of mild steel. . . . . . . . .
>The 55 tonne Leopard was fairly close to the 50 tonne Chieftain in HP to
>weight ratio, but the ballistic protection was inferior on the Leopard and
>it.... "relied heavily on sloped armour and agility for protection."
>Leopard was a great tank, no doubt about that, but short of the same quality
>as the Chieftain.
>
Actually very close, MVEE Chobham for a Mk 12 FV4201 give it as 55.8 tonnes
(61.38 US) operational and 52.8 tonnes (58.08 US) shipping. The power/weight
ratio is 9.8kW/ton (13.14 HP/ton). The L60 engine is rated at 720 HP gross at
2250 rpm.
>The UK believed a 30 mm Rarden could penetrate the side armour of a Leopard
>and evidence suggest this was probably right. The Leopard's 105 mm L7A3 was
>a hard hitting weapon for sure, however the British again had the edge with
>the 120mm L11, an excellent gun and made better with control stabilized by
>servos and electronics. This provided excellent control on azimuth and
>elevation, a feature which became a standard on later models. The metal in
>the gun barrel was also an innovation, via ESR or electro slag control that
>eliminated most impurities and enhanced the tensile strength of the steel.
>(A marvel of British engineering)
>
There is no way of checking but current claims suggest the 30mm Rarden is
capable of penetrating side and rear armour of current known in-service MBT's.
Finally, after the complete mis-understanding of tank guns and their task in
W.W.II, those responsible were finally shamed into action and produced the first
hint of success with the all too few 17 pounders, although these, fitted into
M4A4 variants only, needed the support of regular Shermans with HE capability
whilst the 75mm Shermans needed the Firefly M4A4 to take on Panthers and Tigers.
Throughout W.W.II the US and especially the UK were afflicted with a blinkered
think small attitude and continually failed to connect the relationship between
turret ring diameter and gun calibre, big guns need recoil space.
Subsequently ROF truly got its finger out and designed a very successful range
of tank guns with the 20 pdr through the 105mm Centurion gun to the FV4201
120mm. Incidentally there is no way of mathematically equating the "pounder"
designation to calibre as its the initial design concept weight of the
projectile, but we do know the 17pdr is actually 76.2mm, the ubiquitous 25 pdr
is 88mm, the deadly-if-we'd-been-allowed-to-use-it 3.7" (94mm) AA gun is a 37
pdr so a rough guess puts the Centurion gun at c. 80mm.
Centurion gave birth to the MBT concept being designed as a Tiger killer if the
invasion had gone pear-shaped although the Allied planners at the time were
still calling for out-moded design philosophies of light, medium/cruiser and
lumbering infantry tanks, Centurion proved so good that all this was finally
swept aside although many voices were raised about impending mobility problems
until the tank fully vindicated itself in Korea.
The petrol engine is not the liability it seems with careful design, two
Centurions were abandoned at the battle of the Imjin River, Korea, and shelled
with 50mm AP to avoid capture, neither would burn and both were subsequently
recovered. Tank engines get a very hard life and the lightly rated 650HP Meteor
(unsupercharged Merlin) needed a programme of improvements to make it wholly
reliable and long-lived.
The Horstmann suspension that now seems to be the accepted method affords quick
repair after mine damage being a detachable bogie/suspension unit and allows a
lower profile than torsion bars, the design continues through Chieftain to
Challenger.
Centurion was sold to 14 nations and fought very successfully by several of them
being updated with newer suitable diesel engines as these became available, the
truly prodigious thirst of the Meteor being the one continual drawback, in
Vietnam the Australians actually managed 15gpm in the jungles.
>From 1945 to 1967 some 4,423 production vehicles were made.
>According to many credible sources the Chieftain was the best MBT in service
>in the world during the 1970's. As far as the "horrendous engine
>failures"... well this was true enough early on, 90% were lost in one day in
>Germany, but the remedy came in an improved L60 multi-fuel engine with
>upgrades in the air filter system. Such failures were never seen again.
>Unfortunately the L60 suffered a bad reputation as a result, something which
>was not deserved as the later models proved very reliable.
>As to power, well the weight ratio speaks for itself. Always about 20 hp per
>tonne, not bad at all really.
>
Chieftain was an excellent MBT but let down by the initially dreadful
engine/automotives, the legacy of which it never recovered from. We can blame
British Leyland for many unmitigated pieces of dross but the L60 Junkers style
opposed piston two-stroke diesel was a ROF design foisted on them, ROF are very
good with hulls and guns but not engines. The list of L60 design failures is
long and depressing but eventually, and probably too late, it came good.
Richard
(Southampton - England)
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