Centurion ARV Mk. 2, FV4006

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Centurion ARV Mk. II on display at Worthington Park.

Known in Canadian service as the Tank, Recovery Vehicle, Centurion Model FV4006 Mk. 2, the Centurion ARV was used in some numbers by the Royal Canadian Electrical and Mechanical Engineers in the recovery role during the years that the Centurion gun tank was in Canadian service. An ARV is perhaps one of the most important support vehicles in any armoured formation as it's task is to recover casualties from forward areas that can, often as not, be under enemy fire. The Centurion ARV Mk.2 was developed by Great Britain and could be based on the chassis of the Centurion Mks. 1, 2, 3 or 5. It first went into service with the British Army in 1956, and a short time later in Canada.

The conversion involved replacing the turret of a standard Centurion with an armoured superstructure which enclosed a winch and crew compartment. The winch was powered by a Rolls-Royce B80 auxiliary engine that was mounted within the superstructure itself. The B80 drove a generator which in turn powered an electric motor which was mounted beneath the winch assembly. The electric motor drove the winch by means of a chain drive mechanism. The winch was capable of a 30 ton direct pull or up to 90 tons when using 3:1 tackle.

An auxiliary fuel tank holding 102 gallons located in the left front of the hull, replaced the water tank and 20 round ammunition bin from the gun tank version of the Centurion. The additional fuel tank was a necessary addition to alleviate the limited range of the ARV when towing a casualty. Even then, it was not uncommon for the it to use 5 gallons of fuel per mile in ideal towing conditions and up to 10 gallons per mile in cross country moves.

A spade type ground anchor was fitted to the rear of the vehicle for use during direct rear pulls of a heavy nature. An "eye" was welded to each of the side plates at the rear of the ARV for use in anchoring the vehicle when recovering vehicles of up to 20 tons from the side. Fairleads and pulley guides were mounted on the roof of the ARV to facilitate front recoveries and also so it could recover itself from a bogged down position when necessary. As it was often necessary to push a casualty, a wooden bumper bar was included on the front of the vehicle. It was mounted in a square steel socket welded to the lower front plate of the hull. An optional two piece jib capable of lifts up to 10 tons could be mounted on the front of the ARV and this enabled the ARV to remove the turret of a Centurion gun tank but it was virtually never used in Canadian service. There were several large stowage bins, two of which ran the length of the superstructure along either side, in addition to smaller ones on the front plate of the superstructure. Other stowage bins and metal baskets were located on the rear trackguards and over the mufflers. Each ARV also carried acetylene torches for cutting and welding jobs that the crew might encounter in a recovery operation.

The Centurion ARV served for many years in the recovery of armoured vehicles in Canadian service but as with any vehicle, it had certain shortcomings. The crew compartment was cramped to say the least, and the commander's field of vision, when buttoned up, was very restricted. When hooking up to a casualty, it was preferable to back up to it, secure the tow cable and pay it out by moving ahead, but in circumstances where a casualty was bogged in marshy ground; the crew was forced to pull the cable out by hand. The winch operator was often in a poor position to actually see the casualty he was engaged in recovering and he was forced to rely on directions from other crew members.

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Winch Assembly illustrating the cramped crew space.
The auxiliary engine which drove the generator that powered
the winch is in the right foreground. The generator and
electric motor was located beneath the winch drum.
To replace the winch cable, the roof section had to be removed.
The winch drum was at the fore end of the compartment.

Specifications

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Winch and crew compartment as seen from the engine deck.

Eric Lusk was a crew member and commander on a Centurion ARV in the 1960's and has supplied the following reminiscence on driving the ARV:

I spent several years driving and crew commanding the Centurion ARV, and while I enjoyed it at first, the "Mr. Recovery" handle wore mighty thin after awhile. I started driving the ARV with B Sqn LDSH in Germany in '66 as a young Craftsman. In those days, I chummed around with the Armoured Corps guys, because most of my RCEME pals were married and lived off camp. Among the tank drivers, skill was measured by one's ability to shift gears up and down without grinding any, and that was no small feat, I can tell you. But first, I should give you an idea of what driving a Centurion was like.

As you'll likely know, the tank (and the ARV) were powered by a V12 Rolls Meteor engine, an adaptation of the Merlin engine which was widely used in British aircraft during WW2. The transmission was a Merrit-Brown 5 speed gearbox with two reverse gears, and with the added feature that the gearbox could turn the tank in neutral. Legend had it that this neutral turn feature drove the inventor crazy, because he couldn't figure out why it did so. I suspect the man was slightly left-of-center when he built the gearbox in the first place, because it was a horror of planetary gear systems. The clutch was a triple dry-plate Borg and Beck, extremely heavy-duty, and it took a fairly powerful leg to depress the pedal. All of the above were situated at the rear of the tank and were linked to the driver's compartment by long rods to the control pedals and levers.

By today's standards, the driver's compartment was primitive. The driver sat on a lightly padded, adjustable seat with the gearshift lever between his knees. The steering levers, or tiller bars, were on the left and right sides of the seat and one had to reach down to pull them. The foot controls; clutch, brake and accelerator, were in the normal locations on the floor. The speedometer, tachometer, and miscellaneous gauges were located beside the switch and fuse panel, on the right side of the compartment, and just below the hatch opening. I have no idea why a speedometer was included in the gauge cluster, since absolute top speed was about 21 1/2 MPH; well below the speed limit in any country.

To drive the beast, one normally started off in second gear, first being reserved for very steep hills or slow crawling. Shifting up was done just before the governed RPM of 2250 was reached, because above that, the engine would begin to backfire due to shorting out of the magnetos by a spring-loaded grounding device in the magneto rotors. To shift, one had the option of double clutching up and down, but to gear up using this method caused a loss of vehicle speed to inertia (remember, the Centurion Mark 11 weighed something on the order of 56 tons). Most drivers, including me; once I'd mastered it, used the tiller bar technique. When the left tiller bar was pulled, it activated the steering brake which was attached to the transmission. This had the effect of slowing one track and speeding the other through the planetary gear system. The momentary slowing of the gear action allowed the driver to slip the gearshift lever into a higher gear without clashing. In practise, this had to be done very quickly to maintain speed, so the procedure was to depress the clutch, slip the lever into neutral, give a short pull on the tiller bar and at the same time, jam the gearshift into the higher gear, and finally release the clutch pedal.

All of this was done in a few seconds, much less time than it took to read about it. Gearing down was done, almost always, using the double-clutch method, with a shot of gas to speed up the transmission when the gearshift was in neutral. It took a lot of practise to master the technique, and driver trainees routinely burned out clutches or destroyed transmissions while learning. So much for the basics of Centurion driving.

Driving an ARV was somewhat trickier when a casualty was in tow. The added weight of a tank hooked onto the back end created a whole new set of problems in terms of inertia and momentum. As you can imagine, the additional 56 tons made for far greater stopping distances, a lower gear selection cross-country and uphill, and cornering, came with a whole new set of rules. The turning radius of the ARV, like the gun tank, depended on the gear selection. In first gear, the turning radius was small, while in fifth, one needed a lot of real estate. This was because of that damn planetary gear system in the transmission. When towing a tank, however, the inertia added to the turning radius, so that a corner that could be negotiated in second by a gun tank, was a first-gear corner for an ARV with a casualty. Often, these types of corners took several attempts to negotiate. Driving through towns and cities in Germany could be hair-raising experiences and more than one car parked alongside the road was left with a souvenier of our passing! During one night move in the annual NATO exercise, traffic control was done by the German police and their regional auxiliaries. The squadron had to drive through a town and a sharp right turn had to be made at an intersection. The German cop had his green and white Porsche parked on the left side of the street we had to turn down, and he stood in the intersection holding up civilian traffic while we went through. One of the tank drivers tried to negotiate the turn in third or fourth gear and almost made it before his left track crawled right over the Porsche! The ARV was normally the last in the column, and when we got there, the tank had carried on, leaving behind a Porsche with a much lower profile and a street covered in gas from a ruptured fuel tank!

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Spade anchor in the travelling position.

Eric Lusk continues his narrative with what it was like to crew a Centurion ARV:

The Centurion ARV was NOT exactly crew-friendly, unlike more modern ARVs such as the Leopard. Even the gun-tank version of the Centurion offered some crew comforts, such as proper seats for the crew and a little room inside the turret, in addition to a "bivvy" that could be slung on the side skirts, or from the gun barrel as a crew shelter for sleeping. The ARV had none of these comforts and we RCEME guys had to improvise.

The winch house contained a large electric winch with a cable of about 1 1/2 inches in diameter. The winch power was provided by another Rolls engine, the eight cylinder B80, which was tucked neatly under heavy plating on the floor of the vehicle, and was a proper nuisance to get at to do maintenance. Fortunately, such occasions were relatively rare, since maintenance was done based on engine hours, and the average winch operation job lasted only a couple of hours at most. So the B80 didn't normally get a lot of maintenance, simply because there was no need. And a darn good thing too. I had to do a tune-up once and it took nearly a day to remove the plating and radio trays just to get at the engine!

The Crew Commander stood in the top hatch during moves, and there was no comfy seat for him as there was in the gun tank. He either stood on the winch control unit, leaning back against the hatch ring, or he rode with one foot on the B80 plate cover and the other on the winch brake handle. Either way, crew commanding an ARV wasn't the most comfortable job in a Maintenance Troop. The Operator was in an even worse situation. The tiny hatch to the right of the Crew Commander was the Operator's hole, and that's about all it was: a hole. The B80 plate was a scant 3 feet at most below the hatch, so the operator had very little room to sit inside, even if there was a proper seat for him to sit on. Usually, the operator rode with his feet inside the hatch and he sat on the top of the winch house, a miserable job on a cold night move.

Being RCEME, and the very soul of improvisation, we ARV crews came up with ways to make life a little more comfortable. The ARV was equipped with an oxy-acetylene welding set, normally used for cutting thrown tracks or mangled fenders, or whatever. Being Vehicle Mechanics, we all knew how to do some rough welding and scrounging materials sort of went with the territory. So most ARVs were equipped with a "hoochie" on the back deck, made of steel piping and wingnuts; rather like a collapsible tent trailer. With a tarp over the framework, we had a very large shelter that looked similar to a wall tent with a peaked roof. The flaps at the front and rear of the "hoochie" were raised to allow air circulation for the engine during moves and to permit the winch operator to observe the casualty during recovery operations. But when these were closed up at night, particularly after a good long move, the hoochie was snug and warm, sometimes unbearably so, from the engine and transmission heat. On either side of the engine doors were two six-foot long bins used to store the tow bars, shackles and other recovery gear. With some angle iron and plywood, it was a simple matter to construct a bed that would fit over top of the bins, and a chunk of foam or an air mattress completed the setup. The third crew member slept on a camp cot at the rear of the hoochie, usually set up across the transmission doors between the two beds. It was a cozy affair; three beds in a U formation, with about five feet of engine door as a floor to the bedroom, and many a late-night party was held on the back deck. We were the most comfortable crew in the squadron in terms of sleeping arrangements, and we often hosted small gatherings at BYOB parties. The B80 winch engine, in addition to being an effective winch power unit, could be used as a heater for the hoochie. The warm air from the B80 vented up through the engine doors on the back deck, so the first one out of bed on a cold morning had the chilly task of stuffing head and shoulders through the rear winch operator hatchway to start the B80 to warm the hoochie. During one long exercise in which the ARV was stationary for nearly two weeks, we came up with a remote control for the B80, a board with a starter switch, shutoff and throttle and choke controls. That way, we didn't even have to get out of bed to start the engine! One of the crew I was on suggested once that we should drain the coolant from the B80 and replace it with fresh water, and rig up some sort of electric pump to the cooling system, so that once the engine was warm, we could shut it off and then pump up hot water for shaving. We never did try that one, however.

When we went on exercises in Germany, we were usually on "hard" rations for up to two weeks at a time. In the '60s, we were stationed in Iserlohn, in the Ruhr Valley, as part of the British Army on the Rhine. Consequently, our "hard" rations were the British compo packs, which were NOT the greatest. So we, like our gun tank counterparts, usually pooled some cash before an exercise and purchased extra groceries from the MLS store (a forerunner of the present-day Canex). Things like tinned Danish bacon, pork and beans, bread, peanut butter, and potatos and eggs were among the purchases. These groceries were stored in one of the long bins on the sides of the winch house, since we rarely carried all the recovery gear that was issued to the ARV and there was lots of room for the little "extras". For cooking we carried two single burner Coleman stoves, later replaced by a double burner stove. The ARV, like the gun tank, also had an electric boiling vessel, a pot containing a heating element which could be plugged into the auxiliary charging engine (called the CSU, short for Charging Set Unit, I think). This boiling vessel, however, took a long time to heat a pot of water, and was only used when we had no fuel for the stoves. Cooking was done on a rotating basis among crew members, and some were better at it than others. Generally, married guys were better at cooking, having had some experience at it. My approach was to dump a few cans of whatever into a pot, throw on a dash of any spice we had aboard and let 'er brew. This didn't win many accolades, and I was usually given the task of burning the toast over the open flame stove during breakfast. Exercises in Germany were fun, and due to the crowded population there, towns are very close together. We often found ourselves in a town for a night or two, and on these occasions we could visit the local grocery stores and bakeries to replenish our grocery supplies.

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© Chris Johnson, 1997