(From the Armour Bulletin, Vol 18 1983)

SHOULD THE AVGP CARRY ITS OWN SPARE TIRE?

by Capt F. Kuschnereit

Author's note: I wrote this as a service paper when I was a troop leader in the 8^th Canadian Hussars. At that time the Cougar was only a tank trainer. I put this in to the suggestion award program. It made it all the way to NDHQ where it was turned down as it was not thought there was a requirement for it. Since then the Cougar has been employed as an armoured car in Somalia and Bosnia. The troops there found they need spares and it was easier for each car to carry their own. Unfortunately the new Bisons and Coyotes are being purchased again without enough spares for each vehicle. That is why I dug out this article and resubmitted it to the suggestion award program. It appears to be the only way for NDHQ to look at the question again. It is somewhat ironic that Cougar has been employed overseas in operations while the Leopard tank stays in Canada as a 'Cougar trainer'.

Introduction

The Armoured Vehicle General Purpose(AVGP), at this time, has to rely on first line support to change a flat tire. Although this system works reasonably well in peacetime, I suggest that the present system would probably cause undue delays in a real operation.

The aim of this paper is to resolve whether the AVGP should carry its own spare tire.

An AVGP tire can go flat for any of a number of reasons. The most common is the puncture of the sidewall by sharp rocks or empty casings. When a tire goes flat, the vehicle can still travel on the Hutchinson "run-flat" insert for approximately 50 km at a reduced speed.

When the crew of a vehicle reports a flat tire they also have to report the type of tire as left or right tread. The squadron maintenance vehicles comes to the location after picking up the spare tire from the SPSS Section. The Husky may use a shop jack or its crane to change the flat tire. The actual changing of the tire only requires the removal of 8 bolts. The procedure resembles the way you would change a tire on your family car. In fact, in most cases the Husky is only a delivery vehicle for the wheel and the jack, as the crew does the actual changing of the tire.

The damaged tire then has to be sent back through the Echelon system to the Regt A2 echelon and then back to a second line tire repair facility. Subsequently, a replacement tire must be demanded from second line holdings and brought forward. This procedure must be followed for the repair of each flat tire.

8 CH is allowed to carry only 6 spares at the present time to service 38 AVGPs with a total of 228 tires. In addition, it is not unusual to have a company of infantry and several FOOs attached with a further 17 AVGPs and 102 tires to be maintained.

During RV 83, B Sqn had vehicles out of action for days due to lack of spare tires. The above reference states that "2 Svc Bn scaling of AVGP tires appeared to be inadequate". This was only one Squadron operating on a peacetime exercise. It had an expanded Echelon and the entire Regt's holding of spare tires, and yet this wasn't enough.

If the 8 CH were to engage in actual operations, tires would likely be damaged by small arms fire, shell fragments and mines. Tires could be damaged to such an extent that third-line repair or complete replacement would be required. I suggest that our current scale of spare tires would not support even limited operations.

Advantages

If each AVGP in the 8 CH carried its own spare tire, there would be a total of 38 spare tires (19 left - 19 right) organic to the Regt. With each tire weighing about 400 lbs, this would mean that there would be 15,200 lbs of tires that would not have to be lifted and handled by the Echelon System. Repairs could be affected immediately instead of waiting for the supply system. Currently one SPSS truck is employed with the hauling of spare tires when it could be employed more gainfully.

With the addition of one or more jacks to each troop, tire repairs would be a part of crew maintenance and the mechanics could be employed with the more demanding repairs. This would give the Squadron Commander an assured supply of spare tires, less vehicles out of action and proper utilization of his mechanics.

If the Husky were not required to change tires it would be less likely to come forward and be exposed to hostile fire. The reduced work load would also take some of the strain off of our over-tasked mechanics.

A further advantage would be in the reduction of the number of Hutchinson "run-flat" inserts that are currently used. Since the vehicle is capable of running up to 50 km on the "run-flat", most crews are tempted to carry on with training instead of waiting for a spare. Consequently, the insert is degraded to a point where it has to be replaced at a cost of $400 per unit. If each troop had the capability to change tires, they could replace the tire before the insert was ruined.

Figure 1a and 1 b illustrates a possible mounting location on a Grizzly and a Cougar for a spare tire. If the tire were mounted on the upper left rear of the Cougar hull, it would not adversely affect the vehicle's center of gravity. In fact, it would make the vehicle more stable. We currently have to use ballast when swimming the vehicle since the engine makes the vehicle heavy on the right front side. The Grizzly has more weight to the rear of the vehicle. The spare tire mounted on the left side would still off set the heavy engine on the right front.

The actual cost of the mounting bracket would be minimal as it could be fabricated locally. I suggest that a mount could be welded on the side and the tire secured with wing nuts. The jack could be a small portable model of at least 8 ton capacity. It could be operated either manually or electrically or using the vehicle's own air compressor system. One per vehicle would be ideal, but one per troop could suffice.

FIGURE 1.a

FIGURE 1.b

ARMOURED VEHICLE GENERAL PURPOSE WITH PROPOSED SPARE TIRE MOUNTED

Disadvantages

Some people could argue that the addition of a spare tire per vehicle would cost too much to implement and is not needed. I suggest that RV 81 and RV 83 have proven that tire usage greatly exceeds the original forecast that was made when the vehicles were purchased. With the Cougar now tasked with operational roles, our inventory of tires should be increased to provide realistic operational stocks.

The spare tire is vulnerable to hostile fire when mounted on the exterior side of the vehicle. This is an obvious fault that could be corrected by protecting it with armour or merely carrying it inside the vehicle (in the case of the Cougar which has the extra space).

There are two types of tires (left and right) as the tread is designed to throw mud clear of the vehicle. Within the troop, two vehicles could each carry a left treaded tire and the other two, a right treaded tire. For emergency use, a tire can be fitted on either side.

Conclusion

The present system of replacing damaged tires is inefficient in its use of resources, is too slow and has proven not to work very well, even during peacetime exercises.

Trained mechanics and a specialized recovery vehicles are being used to merely deliver the spare tire and a jack to the vehicle site when they could be working on more demanding jobs.

The task of changing a flat tire should be relegated to crew maintenance. Each vehicle should carry a spare tire and at least one jack should be carried within the troop.

With the increase of spare tires within the Regiment, we would reduce down time, allow the SPSS truck to be more gainfully employed, reduce the work load of our mechanics, have an assured stock of spares, and generally increase our operational effectiveness. I firmly believe that each AVGP should carry a spare tire.