L60 Engine

#1
Rather than Hijack a thread on Chieftain turret problems, can we continue the L60 saga here?

As I understood it, there was a problem in the 50s in finding a source for MBT engines.

Previously, MBTs used modified aircraft engines such as the Merlin/Comet which powered the Cent, but by the mid 50s aircraft were moving to jet power and the source of large piston engines was drying up. From what I understand, the L60 was based on a German design - a diesel aircraft engine for bombers built by Jumo which featured the opposed pistons.

The advantage was said to be the ability to vary the compression ratio by changing the timing of the two crankshafts and hence provide a multi-fuel capability.

The Yanks and the Swedes of course went the gas turbine path...

By the 70s when the next generation of MBT were being designed, the big truck industry, headed by MAN and Volvo were starting to build big engines again so the current generation of MBT were back to conventional designs.

Can anyone confirm/deny ?
 

elovabloke

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#2
The L60 was mounted in the Big D series of train engines in the UK. Mounted in pairs and constant reving and they worked like a dream. As did most of the ones that hauled my arrse around the country side. People forget that the pack life was twice that of a Leopard but it was just such a bitch to change.
 
#3
M&S Dumfries have (had) one as their emergency generator engine.
 
#4
It was designed to be run at constant speed/variable load so as a train engine or generator engine it would have been fine. The problems started when it was then pressed into use as a variable speed variable load engine in a tank.
Same thing with the original CV12. It was designed to have a small genny being driven by it.....then they whacked on a dirty great 500 amp polyphase genny. They then compounded the error by using a load priority instead of a load sharing system. Result? sheared genny drives, snapped drive chains etc etc etc
 
#5
One of the better ideas was the mod to retain 5 gallons of oil in the pack after shutdown. Mind you no-one told me about this when I came back to a Sabre Squadron from Comd Tp. I had to make a cringing apology to the driver after berating him for the "low" reading on the dipstick (unmodded). Oops.
 
#6
The two crankshaft - opposed pistons conept is very much like that in the Deltic engines. These, originally designed for marine use, found fame as raliway locomotive engines. They had three banks of cylinders, three crankshafts geared together and six pistons per cylinder set. Confused?





Here's one of the locomotives - they had two of the units pictured above at 1650hp each.



According to wikipedia, the original Napier Deltic Marine engine was derived from the German pre-WWII Junkers Jumo 204 aircraft diesel.

See the Wikipedia article here. (Well worth a look - lots of interesting links)
There's a slightly frightening 3D animation here

It's hard to imagine that there wasn't some interaction between Napier and Leyland in producing the L60.
 
#7
EX_STAB said:
The two crankshaft - opposed pistons conept is very much like that in the Deltic engines. These, originally designed for marine use, found fame as raliway locomotive engines. They had three banks of cylinders, three crankshafts geared together and six pistons per cylinder set. Confused?
Sod timing that thing.
 
#8
I have vivid recollections of my D+M instr telling me that Chieftain was based on the old 'Cent' Hull, and that the Pack bay was the same size, I remember him saying it was a 'loco engine', and once they had chosen the GUE, they tasked David Brown to design a gearbox to fit in the available space.. I must admit, from those 'top up motor on' days, I totally believe that was the case!
However, I loved Chieftain (as cold and miserable as I got during those pack changes..) It was a drivers Tank, and could be fixed with either a bit of 'Don 10', a couple of miles of 'black nasty'. (won't go into Oils. can anyone remember 'B.H.S.'!)
I reckon its only downfall was the fact that the pack was designed to be 'gently' brought up to the specified RPM and stay there...
As opposed to... 'YOU MUST REACH FOURTH GEAR IN THE LENGTH OF THE VEHICLE!!', (I have muckers in the Infantry, that dreaded the 'Scream' of the Chieftain, because you never knew exactly which direction it was coming from..)
She was a fine Tank, which was proved during 'Yom Kippur' (not sure if I spelt that right) I have seen the pics of T55 rounds hanging out of the Armour of the Israeli tanks.
Just a shame that during the Arms Control days of the early Nineties, I witnessed many 'Concrete filled' Chieftains being dumped off the South Coast... :thumbdown:
 
#9
I don't think Israel had Chieftain. Centurion, yes. ISTRC that Israel did want to buy Chieftain, but HMG turned them down. So the Red Sea Pedestrians went ahead and developed Merkava off their own bat.
 
#10
Trackpen said:
I don't think Israel had Chieftain. Centurion, yes. ISTRC that Israel did want to buy Chieftain, but HMG turned them down.
The Israelis helped to design Chieftain - they were one of the original planned customers, and having fought Centurion in the 1967 war (and not having a domestic tank industry), were full of ideas about how to improve things.

So, having helped to specify it (after all, it was going to be facing the same Russian tanks, either over the Suez Canal or the IGB) they were rather upset in 1973 or so when Britain decided not hold up our end of the deal and sell it to them, because we were trying to stay sweet with OPEC during an oil crisis. Shame that, we could have sold them Challenger in the 1980s and CR2 in the 1990s 8O

The Israelis promptly set up their own tank factories, designed the Merkava (the Mk.1 used the same gun as Centurion, but then so the first model of the American M1) and they're up to Mk.4 now...
 
#11
Gravelbelly said:
Trackpen said:
I don't think Israel had Chieftain. Centurion, yes. ISTRC that Israel did want to buy Chieftain, but HMG turned them down.
The Israelis helped to design Chieftain - they were one of the original planned customers, and having fought Centurion in the 1967 war (and not having a domestic tank industry), were full of ideas about how to improve things.

So, having helped to specify it (after all, it was going to be facing the same Russian tanks, either over the Suez Canal or the IGB) they were rather upset in 1973 or so when Britain decided not hold up our end of the deal and sell it to them, because we were trying to stay sweet with OPEC during an oil crisis. Shame that, we could have sold them Challenger in the 1980s and CR2 in the 1990s 8O

The Israelis promptly set up their own tank factories, designed the Merkava (the Mk.1 used the same gun as Centurion, but then so the first
model of the American M1) and they're up to Mk.4 now...
The Russains, managed to steal an L60 or a Chieftain, so legend has it & tried to copy the L60, but had a few problems with it apparently :? :? Also one of my OC's, father who also served in the military, were involved with the development of our favourite panzer. At the time RR were going to supply a purpose built engine for it, but needed about another 6 months for it to be fit for their name to be put on it. At the same time, Leyland were in their normal mess & the Labour government at the time got them to supply the engine instead just to bail them out of trouble. My OC's dad resigned in disgust at that decision. How times have changed.......not :x
 
#12
Trackpen said:
I don't think Israel had Chieftain. Centurion, yes. ISTRC that Israel did want to buy Chieftain, but HMG turned them down. So the Red Sea Pedestrians went ahead and developed Merkava off their own bat.
I'm fairly sure you're right in this, however, there were, allegedly, some(3?) on 'trials' at the time of the er... unpleasantness. This, of course, could well be apochrypal.
 
#13
Trackpen said:
I don't think Israel had Chieftain. Centurion, yes. ISTRC that Israel did want to buy Chieftain, but HMG turned them down. So the Red Sea Pedestrians went ahead and developed Merkava off their own bat.
You are right Trackpen, It was Cent pictures I saw, I stand corrected mate!
 
#14
PE4ROCK I'm fairly sure you're right in this, however, there were, allegedly, some(3?) on 'trials' at the time of the er... unpleasantness. This, of course, could well be apochrypal.

ISRAELI MILITARY HISTORY

At that time, in 1966, Britain came forward with a dramatically historic proposal. The British needed money in order to complete the development of their new tank of the future, the Chieftain, with its 120-mm cannon. This tank was designed to be the strongest and most modern in the west. In view of their financial constraints they proposed a "package deal". According to this deal, we would buy hundreds of obsolete Centurion tanks. They, in exchange, would allow us to participate in the final stages of Chieftain development, would sell us Chieftains, and would help us build, in Israel, an assembly line for Chieftains. This was seen as an ideal solution to the unacceptable predictions regarding the middle-eastern armor balance from both quantitative and qualitative points of view.

Our cooperation with the British lasted for about three years. Two prototypes of the Chieftain tank were delivered to Israel. Israel invested heavily in the improvement and final development of the Chieftain in close cooperation with British officers and engineers, who worked with us in Israel.

However, Arab states intervened. They threatened Britain with sanctions, with pulling their monetary reserves out of British banks, and other actions. Demonstrations were held in Arab capitals and British embassies were attacked. In November 1969 Britain withdrew from its Chieftain deal with Israel.
 
#15
Fantastic subject. My understanding is that Leyland were made project leaders on Chieftain and so ensured that they put their L60 engine in the vehicle.

It was a LABOUR Government (scu*bags) that refused to sell Chieftain to the Israeli's. The result affected all of us for years. If you recall the Israel's bought Centurion and thought " decent tank" and immidiately put a new diesel engine ( American) in it and new suspension and suddenly this decent tank was a fantastic tank!.

If we had sold Chieftain to Israel in 1969 and they had thought "decent tank" but lets put a good engine in it and better suspension surely with Chieftain being such a new tank and the Israeli version so much superior to ours, any government even a scumbag Labour government would have been forced to upgrade our tanks to Israli standard. You never know all the European counties that replaced Centurion with Leopard 1 might well have gone down the Chieftain route. £billions in export orders lost.

Harold Wilson we thank you NOT!
 
#16
I believe the Shah of Iran had just taken receipt of a first batch of Chieftains when the mad Ayatollah staged his coup and as a result the government of the day were left with a windfall of a batch of tanks ready for delivery and payment already received. Don't know what happened to the tanks already in Iran - probably sold to the Soviets!
 
#17
Innit fascinating how political interference can cast such a long shadow..!

I was not aware of the Israeli angle, but it does not surprise me. I bet the French would not have been so particular.

I was aware of the Deltics in the minsweepers.. got to see around Chiddingford at Faslane about ten years ago. It had three - two for propulsion and one for generating power for sweeps and other "stuff". Struck by how small they were.

Yet again an example of cracking Brit engineering not being fully exploited !

Were L60s ever run on Petrol (Combatgas)? I know Cents were, but that most A vehicles were running on dieso by the mid 70s...

I remember crackin fires in Mk 1 432s along the exhaust pipe - the thought of petrol in an MBT worries me?
 
#18
HE117 said:
Were L60s ever run on Petrol (Combatgas)? I know Cents were, but that most A vehicles were running on dieso by the mid 70s...
Muti fuel but nobody was that silly.
 
#19
They were.....but not deliberately. I was with FRG33 supporting RTR in Batarse in the late 80's. Some fnuckwit filled most of the tanks from one squadron with benz (it was an infantry battle group and the oppo didn't know any better) things got so bad that all callsigns from the FRG were in one spot with packs being shuttled out to us and tanks making their way to us under their own power, if only slight contamination, or towed if seriously fubarred. The sight of a plainly unhappy Cheify banging farting and spouting flames from its exhausts will stay with me.....as will the sight of a pack changed by the Cheiftain ARRV crew sat on its transport cradle as they drove off. The vehicle commander had been an ARSE and made snotty remarks about not letting the FRG work on his wagon. Oh how we laughed as he drove off leaving us with his old pack...complete with the PTO drive collar still attached to the lower damper. All of which meant that when he tried to use his dozer or winch, he'd be in for an unpleasant surprise. We did consider getting hold of him on the radio for a few seconds, but then thought NAH!, leave him to find out for himself.
 
R

Reversionary_Modes

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#20
A story I remember hearing about Israeli attempts to acquire Chieftain concerns trials that were taking place in Sinai in 1973 when the Egyptians came storming across the Suez Canal & the Syrians attacked through the Golan Heights, catching the IDF by surprise. Initially, then, Yom Kippur was not going so well for the Israelis.

A worried MOD contacted the IDF, requesting them to "remove Chieftain from the area of conflict".

A day or so later, the IDF had turned the tables on both Egyptians & Syrians & the MOD received a laconic reply:

"Not to worry: conflict removed from area of Chieftain."
 
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