The first in a new series by Ron Cater
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ARROW BULK CARRIERS
'ONE of the major factors in the current increase in haulage costs is the loss of vehicle use caused by the appalling shortage of spare parts." So said Mr. E. W. Tomlinson, manager and director of Arrow Bulk Carriers Ltd., and Eastaugh Brothers Ltd., the 54-vehicle tanker firms based at Hull, Yorks, when I visited him and his fleet engineer, John Dawson. recently to see how Arrow was tackling some of today's transport engineering problems. But this was, he told me, also the official view of a special working party set up by the bulk liquids group of the Road Haulage Association to probe the detailed reasons for continuing soaring operating costs, of which party Mr. Tomlinson wat a member.
The statement is more than ever relevant to current engineering problems when the reliability which companies like Arrow have always striven to achieve has been joined by new legal standards of vehicle roadworthiness.
John Dawson's task is made easier by a wonderful team spirit which prevails in the companies. There is none of the battlefield atmosphere so prevalent between engineering and operating departments in many transport organizations.
The Arrow engineering department is set up as a separate company known as Ash Grove Motor Engineers Ltd.; all work done for the parent company is charged at full rates, providing realistic comparison with jobs done by outside firms away from the headquarters.
Arrow's foresight, and its readiness to tackle quite extensive modifications in order to get what it needs, are very well illustrated by the way it reacted to plating and testing. This scheme faced many fleets with problems in obtaining adequate braking efficiency from two systems on some of the older machines which were in other aspects still capable of a number of years' useful service.
Few manufacturers were quick off the mark with adequate conversion details and even fewer could quickly provide the parts required to carry them out. Arrow management saw immediately that if conversions were not tackled urgently there would come a time when too many vehicles in the fleet due for plating and testing had not been converted. So, rather than wait for the makers to come up with the answers they needed. John Dawson got cracking with his own design alterations. He saw quickly the inherent advantages of the spring brake with its fail-safe qualities and ease of installation, and most of the rigid eight-wheelers in the fleet (four 24-ton AEC MK Vs, and eight Foden 24-tonners) were quickly fitted with spring brakes on their rear bogies. In both cases the results were encouraging, and retardations achieved were close to those obtained with the main systems.
Simple conversion The conversion on the AEC vehicles was simplicity itself, for the Berg spring chambers bolted straight on to the existing chamber brackets without any alteration. The only problem which arose was that the original brackets flexed under the maximum power of the spring chambers, and because the original steel piping had also been used—this again was a perfect fit without alteration—the stresses passed into the light-alloy casings around the pipe connections, caused them to crack. The remedy was to fit flexible piping, and no trouble has been experienced since.
The Foden conversion was a bit more complicated, for it entailed superimposing new carrier-plates on the existing chamber
brackets and manufacturing cranked levers to transmit power to the camshafts. In this instance the makers were able to supply the special levers once Arrow had perfected the arrangement. To clear the very much bigger Berg chambers it was necessary to turn the uppermost shackle-pin assemblies round so that greasers and nuts projected on the outside of the chassis instead. of on the inside as is usual with the Foden.
Like the AEC conversion, the one on the Foden has proved completely trouble-free and not one vehicle has failed to meet the braking requirements with ease when submitted for testing.
Making such a quick start with the section of the fleet that had to be converted has enabled Arrow virtually to complete its plating and testing programme to date without once being placed at panic stations from the vehicle availability point of view—no mean achievement with a fully committed medium-size fleet, in my view.
On some of its older tank trailers, Arrow has Scam mell stacked-rubber-suspension running gear. Although the company is basically satisfied with the service from this, the high incidence of brake adjustment required was felt to be unacceptable. There was also a problem in obtaining adequate braking efficiency with the existing Scammell system on these fairly elderly units, using a fifth-wheel dolly-operated crank and cable transmission of power to the brake lever units. Adjustment was needed several times a week to keep an acceptable level of performance; and when brakes were at their peak efficiency, sufficient reaction was set up in the walking beam to raise the rearmost wheels clear of the ground. Neither point was acceptable from an operating point of view, and the latter one should, in my opinion, result in failure at the test station. Late one night John Dawson mocked up in cardboard a brake-chamber bracket which would fit on to the walking beam in a position to permit a chamber to be linked direct through a rocker to the brake lever. The bracket was fabricated out of 0.5in plate (all that was available at the time) and the rocker made up out of an old Albion spring shackle and pin. It was mounted on the vehicle and proved to work well. Later four units, in two handed pairs, were made and fitted.
Type-24 brake chambers were used and when the outfit was road-tested the trailer leapt into the air and, according to John, left a half-pair of tyres on the road! But it was a simple matter to install a pressure-reducing valve and bring the performance to an acceptable level. Since this was done the braking performance has been among the best in the fleet, the need for adjustment being no more frequent than on any other type. Double-diaphragm chambers took care of the secondary system and by leaving the original mechanical linkage in position, sufficient handbrake power was obtained through the single-pull lever to the trailer brake to park the outfit fully laden on a 19 per cent gradient.
Arrow's choice of equipment shows sensible regard for a combination of reliability and economy. In the firm's early days Scammells were reckoned to be the best vehicles for the job, and so the maximum-capacity section of the fleet started with Gardner-engined Highwayman tractive units, and tanks mounted on Scammell stacked-rubber-suspension running gear. These vehicles gave yeoman service and formed the basis for further similar purchases. However, Leylandengined versions of the Scammell did not prove as economical or reliable as the earlier models on this tank work, although they offered better performance on the road. Subsequent maximum-capacity purchases have been Fodens and, latterly, ERFs, though at least one of the newer Scam mells has recently been re-engined with an LX150 in place of the 0.680.
The latter conversion entailed quite a few modifications, notably to the engine mountings. Also, twin smaller air-receivers have replaced the original single large air chamber For the braking system which could not be accommodated with the Gardner exhaust layout because this is on the opposite side from that of the Leyland engine.
One advantage which Arrow expects is that troubles stemming from the air-assisted clutch will disappear. The air pack for this has been a source of trouble, while the ramifications of incorrectly operated clutches were amply evident in the workshops where 1 saw two damaged gearboxes which had lain stripped for months awaiting replacement parts.
About £15,000-worth of spares is currently held in the Ash Grove stores, which I thought a high figure for this size of fleet. But I was told that the problem of obtaining spares was such that a storeman had to be employed almost full-time on phoning round for spares. An estimated 30 hours a week is spent by the man on this—costing the firm perhaps /15 in labour alone, to say nothing of the telephone charges for calls which are often long-distance. Difficult as it is to locate parts, it is sometimes even more difficult to get one's hands on them and Ash Grove employs two small vans mainly on spares collection. I found from the records that these two vehicles had long averaged 1,000 miles per week and even at the low figure of Is. a mile this puts £.50 per week on the firm's operational bill—without including wages.
As 1 walked through the stores with John Dawson I was surprised to see a certain make of driving axle lying, obviously new, on the floor. I commented that in all the years I had dealt with the type I had never seen the inside of one, and that I was amazed he should find it necessary to hold one. His answer was on lines which are not unfamiliar. The Orticular type of unit had, after many years of trouble-free service, recently been "value engineered" and one of the alterations made was to substitute some form of plastics spacing shims for the brass ones originally used in the crown-wheel carrier. The estimated saving, I was told, was about 9d. per unit but the results had been so bad that for the first time in many years Ash Grove had found it imperative to carry a spare—with capital involvement of about £600.
Despite the efforts made to provide for-all eventualities, Ash Grove finds it increasingly difficult to build up a buffer stock of fast-moving parts. Ordering now has to be forecast against factory lead times rather than past performance and local knowledge, and it is not unusual to have to wait 14 days for parts even when these have been ordered on a "vehicle off road" emergency order.
One bright spot in the parts picture is that where operators can still buttonhole an executive of the suppliers, something can nearly always be done quickly.
A second important point relative to increased costs was put to me by Mr. Tomlinson. Because it is so difficult to forecast what the economic life of the latest vehicles is going to be, depreciation periods are very difficult to lay down. Once one could estimate with accuracy the service that a machine would give, but this was no longer possible, he felt; one did not dare to work on a low-cost, and hence low-rate, basis. Operators had to work on the shortest calculated vehicle life or risk serious financial trouble.
Arrow has reduced the basic vehicle service life from 10 to six or seven years now, but makes yearly decisions according to how well or badly a particular type or make is performing from a cost and reliability angle. • However, as 1 have said before, Arrow is quite prepared to tackle major tasks and has been responsible for several unusual alterations to its vehicles in the light of experience. For example, some well-known rigid eight-wheelers were prone to balance-beam trouble after only a very short period of service. The Arrow engineering department looked around to find the best balance-beam assembly for the job and selected the Atkinson. The offending vehicles were quickly converted to accept this unit and in the five or six years since then the conversions have been pretty well trouble-free.
On the maintenance side, the Arrow fleet runs a substantial inspection service, with secndary coverage by greasers, and also takes advantage of the free chassis inspection service which Michelin offers to its customers; Michelin X tyres are used almost exclusively. The inspection covers all chassis parts, running gear and alignment but not running units. No remoulded tyres are used at all, and many of the new vehicles are being fitted with tubeless equipment.
The company has tried automatic lubrication systems, but none of those fitted has gained favour with Arrow. it was felt that they cost as much as they saved, the biggest trouble apparently being that units were subject to unnoticed failure. Lubricant supplies ceased because a delivery pipe came adrift, or because of a blockage to the unit being served, and by the time the fault was noticed the part had usually run dry for a considerable time and the damage was already done.
• The Arrow fleet is now hand-greased throughout at rigidly controlled intervals. Not only does this system ensure that every point which needs grease gets it regularly, but this greasing routine provides the secondary inspection service, increasing the likelihood of faults being spotted before they have gone too far.
All the bodywork used in the fleet is built by Darham Industries, part of the Thompson group. Every unit is made of FMB quality stainless steel and, to cut the cost of cleaning and guard against cargo contamination, all tanks have polished interiors. Pumps and blowers are used, most being of Drum Engineering manufacture. Some of the later vehicles in the fleet are equipped with hydraulically driven units mounted on the tanks, and in some cases these particular vehicles carry both pumps and compressors.