attleej

Dear All, I don't think that the RTR definition of a "tank" is correct or authoritive. The nomenclature for the Conqueror ARV is Tank, ARV, Conqueror Mk II. I am not convinced that it would be effective against another AFV since it is only armed with light machine gun (Browning or Bren, I don't know which for certain). A chief's nomenclature is "Tank, Combat, 120mm Gun,Chieftain, Mk 1". This rather implies that there are other variants which are not combat or gun tanks. ARK, AVRE, AVLAB and BARV come to mind. I am quite clear that the Conqueror ARV is a tank even if it does not have a sticky out thing! John

In a preserved vehicle, even compressions are nearly as important as the actual figures. If they are not more or less the same you have a problem. John

It looks very similar to the one on a Roller. It may be that the pistons etc are the same. John

Gosh! What size and thread have you made the pull off screw. I have the same job coming up on the Antar! John

Dear All, I am surprised that this thread has not generated more interest. I have several conduits on the Conqueror ARV that are rotten. In the Army, and I expect DSG, they will just demand the conduit assembly as one part number. Has anyone got a parts list that gives a NATO Stock Number for the flexible conduit itself, esp the small dia one about 1/2 to 9/16". I could then do some digging. Quite often one has a longer length than required which could be shortened. I do not even know how the conduits are assembled. I have asked at Bordon and got nothing. I suspect that some form of press is involved. John

Dear All, Out of interest, Andy Long's Martian recovery has a Cummins and Fuller RTO gear box which has overdrive. That would take 2200 revs to 2933 which is getting there. The original (and horrible) 4 speed synchro box would have been direct drive top. However, he did have to stretch the front a bit to get it all in. In Dorset (I think) someone has one with a Volvo engine and presumably an overdrive box. One problem with fitting an engine with far more grunt than original is that the transmission won't take it if worked fully loaded. Therefore you see plenty of Scammell Explorers with very nice conversions and yet we know that problems arose with Constructors (with a very similar clutch / gear box arrangement) when running with just slightly more powerful engines. The Leyland Martian Arty tractor looks lovely! I just love the crew cab. In the TA when I was using the Scammell Explorer to support 10 tonners I always dreamed of a Leyland Arty tractor and dummy axle. That was until I got issued a Martian Recovery! John John

Dear All, I had not thought of marine mounts that just shows the value of the forum! I originally fitted the diesel engine in the early 90's. The problem I had then was to design and fit the mountings in the available space when most of the vehicle is together. Another difficulty was a cross member made it very difficult to check alignment. I shimmed the engine side to side and used slots for up and down. It worked but the new arrangement will be much better. The job is so much easier now. You cannot really see it but on each side there are two Series Landrover spring bushes to give a little bit of anti-vibration but a lot of stiffness as I did not want the engine moving around under the effect of torque. The front mountings take care of any chassis flex.The horizontal plate will be slotted to give a little side to side movement. I will centralise the engine with temporary adjustment screws before welding the bracketry in place. Up and down adjustment will be by shims. I need to have the weight of the engine on the mounts to compress them before checking alignment. Unfortunately I have not advanced it this weekend due to work commitments and need to re-organise the workshop in order to improve its productivity. I was not even able to crank up the Conqueror! John

Dear All, I am now working on the rear engine mountings. Since there is a flexible coupling between the engine and the clutch / gear-box assembly the rear mountings need to be adjustable in two directions in order to be able to perfectly align the two. This is the one bit of significant manufacturing that I have to do on the project. I hope to have this bit finished within the next two weeks. John

Sam, The photo shows exactly the set up required. When you look at the prop shaft on a Martian recovery you will see that it is very long. It would be quite easy to put in a short prop shaft and an intermediate bearing. The only reason why I did not do it to my one at the TA was because it was not allowed! It would be an unauthorised modification which they would get very pear shaped about. With this mod she would run at close to 40 MPH. On performance, do not get too worried! I said that it has not got a lot of guts like an AEC which has the benefit of an 11.3 litre diesel engine but is actually only 144 BHP. The snag with the Martian was that there was only one gear for sticky muddy cross country and that was first and low. It would either get through the bad patch or get stuck with nothing in between. If you slackened off the gas in order to regain traction, the engine would stall. With an AEC or a Roller it will just grunt and pull you out. For what you want to do, you would be using a sledge hammer to crack a nut (which is fine) and you certainly would not need low ratio on a metalled road. With anything less than about 8 tons you would not know it was there. If you were going up Birdlip, having an unladen Bedford TM on the back would not make much difference. It would still be very slow and use several gallons of petrol! If you needed to tow a loaded tank transporter up Birdlip you would definitely want to get a good video clip! As for the engine. A B81 is a lovely engine. A straight eight Rolls! What more could one want! Properly set up she should be sweet as a nut. You would need to do something about the diaphragm on the David fuel pump because it will not tolerate the modern petrols with ethanol. I am sure others on the forum can advise. I would not advise messing around with the comp ratios etc. My only complaint about the B81 is that it is not really suitable for such a heavy vehicle. If you found a Martian with a good B81 engine I think that you would have to consider what to do very carefully. If you stuck with the B81 it would be expensive to run. However, even when I was a junior employee of Smiths Industries I found the money for the petrol for the Antar at 1 1/2 to 2 MPG (I changed it because it kept fouling its plugs due to oil). If you looked at the cost of going say 30 miles it is going to use 20 gallons of petrol, about £100. But what fun! If you converted it to diesel you might halve the fuel consumption but the 30 mile trip would still cost £50. If you did 1000 miles in a year (which would be quite a lot for a Martian) a diesel would save £870 but would still cost about the same amount in Diesel. Fitting a diesel requires a huge amount of effort plus the cost of the engine itself. You might well be better working for someone else to get the cash for the petrol. So work out the figures! I hope this is useful. John

Sam, I operated a Leyland Martian recovery vehicle at 240 Sqn at Barnet for many years and so I have a few observations. First of all the winch. Its maximum single line pull is 15 tons. The minimum breaking load of the issued rope was 32 tons. With a 3 : 1 it will pull 45 tons and this is the limitation of the earth anchor at the rear. However, 45 tons is a hell of a pull. Better still it is an exceedingly good winch and in my experience if it did not want to work it was because I was doing something wrong! The rope would always lay on nicely and it had a capstan winch to pull out the main winch rope. A similar, or the same, winch was fitted to the MkIII Antar and that was rated at 20 tons. The crane can be operated at the same time as the winch since both are hydraulically powered. By comparison the AEC could not conveniently jib and winch. In the 80's I thought you would not look stupid if you had the recovery gear of a Leyland on the back of a 6 X 6 Foden. Radiomike7 is correct about the problem of exceeding 30 MPH causing serious aux gear box failure. This problem did not seem to affect the cargo versions. I would recommend fitting an intermediate bearing about 18" away from the output from the aux G box. This would stop the prop shaft whip from hurting the aux gear box. The B81 engine is a lovely engine in the right vehicle eg a Stolly but it has not got enough guts for such a heavy vehicle. On some occasions I was grossing 44 tons with a 6 1/4 litre petrol engine (kerb weight is about 21 to 22 tons). Fuel consumption with petrol would be about 3 MPG but I think that it is very unlikely that you would find a petrol engine recovery vehicle. The engine and its fan make a fab noise! The weak points were: the electrics, I regularly needed to use the starting handle when the starter motor would cut out. The power steering pipe on the right would regularly break. The aforementioned aux box. I never had a problem with the clutch sticking but I was using it every other week end. The brakes were not very good and this was made worse by the small capacity engine. It was certainly great fun to drive. One year 240 and 215 Sqns wre deploying to BAOR via the autobahn. My mate Drew from 215 could not keep up with me although we both had Leyland Martians. I suggested that we swopped vehicles and he still could not keep up with me! He was not a happy bunny but very curious. I then explained to him about the three speed aux box with an intermediate gear. This enables each of the 4 main gears to be split. Therefor I had 8 gears and he only had four! 'Double sticking' is a very odd arrangement for what is basically a 10 tonner. You would normally only expect to find such an arrangement on a tank transporter which needs it due to the very low power to weight ratio. If anyone can suggest any other logic for a three speed aux box in the Martian I would be very interested to hear. If you drive one of these vehicles on a motorway or dual carriage way it is essential to use beacon lights as other road users will not be expecting you be going so slowly. We have an original one at Bordon that I can show you around if you are interested. John

Simon, I can understand your desire to run up the engine before painting. You must be careful to have the ballast resistor in series with the coil if running at 24 Volts or you may burn the coil out. You could just arrange a 12 volt supply for the coil. I take it that you have an FV coil and leads on the engine. If starting it for first time you should fit an oil pressure gauge. Hopefully you should see some oil pressure before she fires up. Do not keep running it if you do not see oil pressure come up PDQ. For quick run-up temp gauge and oil pressure switch might not matter. If you have the starter motor that I expect you have, you need to connect the heavy duty positive 24 volt cable to the starter and the neg to the casting of the engine. To make the starter go you will have to find some way of sending the signal to it. My recollection is that there is a cover that you can remove which will expose the low power terminals. I think that I have posted a paper on FV electrical systems in the electrics section of the forum. I expect that there is other good info around. I don't think that the generator matters so long as nothing is connected to it. Finally, be careful with the petrol. A quick run up with ropey electrics, open exhausts etc is much more hazardous. Have no bigger petrol supply than necessary if you are not using the vehicle's tank. I hope that I am not teaching you how to such eggs! John

Simon, Surely you have a quick release connector to the junction box and the heavy duty cable to the starter. What more is there unless the Champ does not have an electrical system fitted at present. If it does not, one of us can give help. John

Dear All, This is indeed not very much by standards of the recent past. However the good news is that MOD is planning an Ex SAIF SAREEA in Oman and that will be significant. The last one was a godsend because it was just before the Op TELIC and it enabled us to sort out one or two weaknesses. John

Dear All, Most battery isolator switches for commercial vehicles are double pole so both neg and pos are disconnected so no risk even when disconnecting batteries. Some isolators can be switched off remotely, eg the one fitted to the Bedford TM. Having thought about it carefully, I think with a single pole isolator it is best to fit it to the negative line. Always disconnect the earth (usually negative) terminal first. That way, when you undo the pos term it cannot be live to the chassis. I have had a lot of problems at Bordon with leaving the master switch "on" for a few weeks ands so ruining the low maint batteries. On the Conqueror ARV I have fitted a timed cut out so that a Contactor opens after 30 minutes or so. No more problems. Maybe not such a good idea for a road vehicle! Finally, think very carefully about fitting wires for accessories such as a fridge or radio straight to battery, esp with an isolator. If isolator is "off" and you try to operate the starter, all the current could go through the radio supply cable! For that reason, if you draw straight off battery, both neg and pos cables feeding need to be fused with an appropriate rated fuse. John

Certainly 500 amps for starting and 1000 for a short while. I would have thought about 250 amps continuously. You will not have a problem with a battery charger! Much safer to use than croc clips. John

Dear All, I should have added thanks to Glen Freer and Andy Trimmer for helping me get the winch to work and Toby SB for helping me do the winch testing and much else besides. John

Dear All, I thought members might like to see pics of the REME Museum's Conqueror ARV having its winch tested. Note the deep hole the spade dug in the ground. The Conqueror was pulling against the Centurion ARV with its spade dug in. It is very hard to provide an anchorage to resist the 45 ton's pull of the Conqueror's winch. The purpose of the test was to determine if the new drive system could develop the full 45 ton's of pull, set the electromechanical cut-out and to roughly calibrate and test the new winch load indicator. It does pull the full load, the cut-out is set (although I have since disturbed it). However, the winch load indicator requires further development which is now nearly complete. Once everything is working correctly the whole system will be inspected by the 'competent person' and then certified. John

Mark, I talked to the armaments people at Bordon. They had no précis on the turret lift. However, it is not a big problem. Apparently it will take you about a day. The key things are the RJB and being careful not to damage any of the harnesses. There was something about loosening the turret traverse mechanism. The EMER will tell you of anything essential. What are you going to use to lift it? It will weigh around 12,000 kgs at least. John

Mark, I should imagine that SEME have a précis for that task. I will ask when I am there on Friday I will ask. John

Dear All, I would have thought the first step would be to ensure that the vehicle is pulling properly with the engine it has. I take it that it is being run empty or with only a small load. And a very silly question: It has got the turbo charged engine for the MJ and NOT the naturally aspirated MK engine. I also think that it would be a lot easier make 'final adjustments' the FIP rather than fit a different engine. If you do go for an ex mil Bedford 500 (which I don't think is a good idea) make certain that the rear crankshaft oil seal is not leaking. John

In this environment, everyone knows me as John. It does make it a lot easier when you know the vehicle intimately. I bought it in 1983. John

Dear All, Every single nut and bolt has been stripped and re-plated. I then repaired any damage incurred in the strip down process. Doing this is really paying dividends now because it all bolts together so easily. Some of the bolts are 'special' eg the ones securing the drawbar. I can read the part number on them and ensure that they go in the right place. It is proving a little difficult to remove the olives from the air pipes, esp if they are on copper rather than brass tube. However, it is essential to get the tube nuts off for re-plating. All the air brake tube nuts are the very fine thread ones and if they are not re-plated it is hard to tell if they are cross threaded and is generally very unsatisfactory. When the stud and nut is re-plated it is easy. I will try a plumbers' 15 mm tool. Any tips welcome as I have 200 to remove. As I said before all the air pipes are numbered using the same number as the parts list. John

On that weekend at Belvoir I was supporting the Road Rescue Recovery Association. We had two vehicles that had mobility and utility. One was a Bedford MK / MJ belonging to Jon Beech. The other was the Antar. All the commercial recovery vehicles, whilst I am sure that they are good at what they are supposed to do, had winches with relatively short ropes and were very slow. The Antar has 300' of rope and can winch in, or out, quite fast. I think that they were all rather surprised! I have the winch dismantled and it is still in very good condition. As for tyres, they are not a problem. The fronts are showing a some uneven wear but have a bit of life left. The rears are fine. They don't seem to perish much. I do have several 1400 R 24s. Unfortunately they are not all the same size and the Antar does not have a third differential. Running with diff sizes AND high axle weights could cause half shaft problems. The advice I have received is not to try to fit one because they were a bit of a weak point. When in service, it was easy for the Army to keep to one good and equal sized set of tyres on the back end. John

Paul, It was a 265 but after I opened up the fuel a bit it is more like 300. Out of interest, when I visited Rolls at Shrewsbury, the Chief Applications Engineer told me that you could "open up the max fuel screw until it smokes as much as you can tolerate". For sometime, the limitation of a MkIII Rolls was when it started to smoke. When the engine has a designation L eg 290L, it has boost control so it does not deliver max fuel until the turbo has boosted inlet manifold pressure sufficient to stop it smoking. The problem is that it adversely affects the torque curve so that you do not get all the torque just after you have changed up. You will not be surprised to hear that my engine has not got boost control! John

Dear All, In answer to Paul I have only labelled the air pipes because there are so many and there are too many perms and combinations. I used a luggage label for clarity AND a stamped ally disc wired on for security. I want to take off all the tube nuts for re-plating. The threads are ridiculously fine and having re-plated nuts and tube studs would be a great improvement. On the Antar all the bespoke metal parts generally have a part number stamped on them. Most can only be seen / read after plating or shotblasting. Since I bought the vehicle in '83 I know it intimately so I know where most parts go in any case. WRT the fasteners, Thornycrofts used the ideal size to the nearest 1/8" so after plating I sorted them out into size and length. The parts list is ESSENTIAL (don't even think of doing a job like this without one) however, sometimes it shows 3 diff lengths for attaching a part without saying where each size goes! So a bit of detective works is req. In answer to Mark and "Antar" I fitted the Rolls Royce Eagle in about 1992. The petrol engine would continually foul its plugs, even on a motorway. It was certainly not a practical proposition although quite fun to use. I have never heard tell of an Antar overheating. The Mk I and II had twin radiators. Each of them far bigger than any lorry with a Roller in it. I judged that the original fans were not necessary. All there is the one original Rolls fan in the middle and with no cowling. It did not even think about overheating. Not even pulling up Reigate Hill on M25, in July, at 9 MPH at 107 tons gross train weight. The only snag is that it does not make the noise of an Antar! On the other hand, the Contractor does have a lot of fan noise, very impressive but it only does 2 MPG. Using 20 HP to drive the fan probably has something to do with it! John