Plannirtsjor Profit
Page 50
Page 53
If you've noticed an error in this article please click here to report it so we can fix it.
Where Rigids May Score
Maximum-load Fourwheelers Combine 14-ton Gross Weight with Economical Performance
IN recent weeks comparative operating costs have been examined for articulated and rigid vehicles with both platform and tipping bodies. These included examples from the classes of vehicle which have traditionally come to be known as medium and heavyweight.
A recent inquiry introduces a further alternative--the comparison between a medium-weight articulated vehicle and the relatively new type of rigid four-wheeler which, for want of a better term, can best be described as a light heavy-weight. Because of its modern design, it is more economic to operate than its predecessor, but can take full advantage of the increased legal gross maximum weight of 14 tons.
In making this inquiry, the reader stated that the job that he had in mind called for.a. 10-ton vehicle and the weekly mileage would be approximately .500. He then specified the two vehicles and asked for an opinion on the comparative operating costs.
Dealing first with the 14-ton-gross four-wheeler, the initial price would be approximately 0,300 and the unladen weight in the 44-41-ton tax group.
The first of the five standing costs--licences—would amount to 24s. 10d. per week: This allows for two weeks per year when the vehicle was not operated and includes provision for the carrier's licence. Wages would be 178s. 7d. per week, based on R.H. (62) Grade I rates for drivers of 5-10-ton-eaphity vehicles. This amount also includes an allowance for holidays with Pay and national and employers' liability insurance contiibutions.
Increased Premiums Rent and rates are assessed at 10s. a week and insurance at 50s. a week, based on the recently increased premiums with additions relative to the initial cost. Interest at 3 per cent. would be equivalent to 40s. a week.
These five items of standing costs would total £15 3s, 5d. a week or 7.28d. a mile at 500 miles a week.
There will be some difficulty in assessing running costs because of the comparative newness of this particular type of vehicle. Sufficient time has hardly elapsed since its introduction to obtain average figures from a wide range of ,operators, particularly on depreciation.
I have before me. however, an annual summary of an operator's fleet records in which an example of this type is shown alongside the model it replaces. This is particularly useful, as both vehicles run under the same conditions.
Over an annual mileage of 30.000 the older type returned a Fuel-consumption rate of 12.69 m.p.g., as opposed to the later model's 14.56 m.p.g., both vehicles, of course, having oil engines. As the newer vehicle had an elaborate dual-purpose body, including tipping gear, it would he reasonable to assume an even better performance when fitted with a platform body. A rate of 15 m.p.g. has therefore been assumed, which, at a cost of 4s. 2d. per gal,, would give a fuel cost per mile of 3.33d.
Residual Value Lubricants would cost 0.24d. per mile and tyres 1.73d., based on an estimated mileage of 40,000. Maintenance is assessed at 2.44d. per mile and depreciation, calculated on a vehicle mileage life of 250,000 and a residual valueof ±:200. at 2.70d.
These five items of running cost give a total of .10.44d. per mile, which, when added to the standing costs of 7.28d. per mile (when 500 miles per week are operated), give a total operating cost of 17.72d. per mile Turning now to the articulated vehicle, the reader specified a well-known 10-ton tractor unit, fitted with an oil engine and two-speed rear axle, together with 8,25-20-in. tyres and coupled to a popular make of semi-trailer, The cost of such a combination would be approximately £1.750 for the tractor unit and £750 for the semi-trailer, a total of £2,500.
The unladen weight of the outfit would be 4-5 tons. resulting in a weekly licence cost of 28s. 10d., or 45. higher than for the rigid vehicle. Wages, however, would remain at 178s. 7d., as they are based on carrying capacity.
As the reader has specified a 10-ton load, it has been assumed that this would not be exceeded and that the wage rate quoted would be legally correct, although relative to the maximum legal gross weight of 20 tons .permitted for the " artie " he would be legally entitled to carry more. Against this, however, there would be the maximum weight as recommended by the manufacturer to be considered.
Because the " artic " would be longer, rent and rates have been assessed at 15s., but because of the reduced initial Price, insurance is rated at 45s. per week and, similarly, interest is reduced to -30s. per week.
The total of these five items of standing costs is £14 17s. 5d. a week, or 7.14d. a mile at 500 miles a week.
Fuel consumption is again asanned to be at the rate of 15 m.p.g., because, whilst the smaller engine of the articulated vehicle should be more economical, this would be counterbalanced by the higher unladen weight. The cost of fuel is. therefore, the same at 3.3ad. per mile, as also is the cost of lubricants at 0.24d. per mile.
Tyres, again based on a mileage life of 40,000, would cost 2.10d. per mile. This is because the saving on the smaller tyres fitted to the articulated outfit, as compared with the fourwheeled rigid vehicle, is more than offset by the additional number of tyres to be provided.
Maintenance is again assessed at 2,44d. a mile, whilst the last of the five items of running costs—depreciation—is calculated at 3.94d. a. mile.
Total running costs are 12.05d. a mile, which, when added to the 7.14d. a mile standing costs, gives a total operating cost per mile of 19.19d. This compares with the 17.72d. per mile for the rigid vehicle--a difference of 1.47d. per mile in favour of the latter.
Wrong Conclusions
In comparing these results, however, some qualification must be added if wrong conclusions are not to be drawn. Whilst the reader specified a 10-ton payload, he also required a particular rigid four-wheeled vehicle with an unladen weight of 4-1-41 tons. Even assuming that the total kerb weight does not exceed 44 tons, the maximum legal payload could only be 94tons, whereas the " artic " could legally carry the required 10 tons. In fact, it would be limited to this figure only by the manufacturers' recommendations.
Comparing the two depreciation costs per mile-2.70d. for the rigid and 3.94d. for the " artic "—these estimates will no doubt vary in relation to operators' individual experience. I consider the advice given in " 'The Commercial Motor' Tables of Operating Costs" on this matter—a mileage life of 125,000 for the medium-weight vehicle and 250,000 for the heavier class —still to be valid, even though the rigid vehicle dealt with here is of lighter construction than what was originally looked upon as a heavy vehicle.
1 Therefore, despite the lower initial cost of the articulated outfit, because it is depreciated over half the mileage life of the rigid, the depreciation cost per mile is 1.24d. higher, and accounts for the main proportion of the difference in the Operating costs.
If, therefore, the inquirer is not compelled to take a minimum of 10 tons per load, the margin between the rigid and articulateil outfit in this instance is sufficient for the rigid to prove the more econo,mical in cost per ton, even after an allowance has been made for the difference between the 9+-ton and 10-ton oads which could be carried by the rigid and articulated vehicles respectively.
Rigid's Advantage Regular readers will have.noticed that the results shown here in favour of the rigid vehicle appear to reverse the conclusion, drawn from previous articles, in which articulated outfits were shown to give more favourable results than the corresponding rigid six-wheeled vehicles.
The results obtained here in favour of the four-wheeled rigid vehicle emphasize again how important it is to consider every available model (as shown, for example, in "British Commercial Vehicles for the World ") before making a decision to purchase. They also emphasize the need for operators to keep abreast of announcements in The Commercial Motor regarding the production of new models.
In this particular instance, the four-wheeler has operating characteristics not previously available, having a higher carrying capacity than the mass-production four-wheeler, whilst being less expensive to buy and run than the model it replaces, which was suitable for drawbar-trailer work.
In addition to its lower operating cost compared with the " artic," it would provide, a useful alternative where working conditions were suitable only for the employment of rigid vehicles. Moreover, because of its construction, full advantage can be taken of the total laden weight of 14 tons now legally permissible for four-wheelers.—S.B.