A 31-ton "Original Berna " Makes 13.8 m.p.g. Average Fuel Consumption.
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An Editorial mandate was issued recently to the writer to do a one (lay's work hauling paper for
Temple Press Ltd. An Original Berna vehicle was notified to be the, next objective of this series, and the individual who was thus detailed off to net as observer quickly got enticusiastic,, knowing, through general observations from time to irne, that a machine capable or doing much and going anywhere weuld be at his command.
As the following account will I estify, expectations were fully borne out during the actual day's Nvork. A job which looked like being uneasy proved really enjoyable and informative. The machine iii question had periodically, during the past three or four months, graced the frontage of this publishing house, and our engineering instinct caused us, at such times, to give more than cursory glances at t he machine with its " hefty " loads of paper.
Where We Started "Work."
We got into touch with Mr. John Yarwood, the English manager for the "Original Berna " motors, who informed us that we could drop on the machine any day which suited us, and it was finally decided thaf we should accompany the vehicle on some specific occasion when it would be transporting paper, as we have said, to our own publishing house. Mr. Yarwood subsequently informed us that Messrs. Albert Reed and Co.'s paper mills at Tovil, Maidstone, would be a suitable meeting-place for the arrangements to be fulfilled.
We journeyed to Maidstone overnight, in order to be at the loadingup early next -morning, and stopped at that old-time hostelry " The Ancient Bell," established in -the. year 1669, 4/1 d mentioned by Samuel Pepys in his diary. In the course of conversation there., we found more confirmation of the fact that motor transport in Maidstone is going ahead, and that its advantages, both from the passenger and goods-transport points of view arc; fully recognized. The machineS in use there are meeting with a considerable amount of favour amongst tradesmen and others in that part of the country. This side issue, of course, further " tuned us up " to our work next day, as we felt we should then be in a position to enable the machine to show its powers amongst many other makes which we should of necessity meet during the trip, Early next morning saw us at the paper mills, accompanied by a pho tographer----on a motorcycle—who was detailed to follow the Berna in order to secure pictures under all possible working conditions, and unobserved by the driver or other occupants of the front seat. -We reached the yard as the driver was filling up fuel, a careful check of the quantity being noted.
The Machine Shortly Described. It is a standard 3,--tonner, made by the Original Berna Motorwa,gen leabrik " of Olten, Switzerland, the sole conc-essionnaire for the United Kingdom and Colonies being John Yarwood and Co., Ltd., Bramber Road, North End Road, Fulham, S.W. The engine is a fourcylinder unit, the bore and stroke being 105 mm. and 160 mm. respectively. It is rated at 30 b.h.p. Its cylinders are cast in pairs, and all the valves are disposed on one side of the engine.
For eliminating friction as nitwit as possible, the crankshaft, is mounted on three ball bearings of ample dimensions, and the connecting-rod big-ends are lined with white metal of good quality. The forced-lubrication system. is. here adopted, the means for oil distribution being a small rotary pump suitably disposed in the engine, crankcase, and this ensures perfect lubrication of all necessary parts of the unit.
The cooling is. effected by a centrifugal pump, which delivers water
to a radiator of the honeycomb type which, we noticed, has an exceptionally-large cooling area. The advantage of this was very favourably demonstrated during the day's work, when many severe hills were climbed un-der our obs-ervation.
A leather-to-metal clutch transmits the engine power to a gearbox, in which provision is made for four speeds, the top drive being direct. The shafts in this unit, too, are carried on ball bearings. The gearchange mechanism is fitted with interlocking devices, and it was most remarkable how easily the gears were changed under all conditions, the onlydifference, which we noticed being the varying speed of the machine as the hand lever was manipulated.
Favourably Impressed by the Final Drive.
We were very favourably impressed by the Berna final transmission and back axle, in that the transmission set is in no way subjected to the useful loads carried, a separate dead type of axle of ample rectangular section being incorporated solely for accommodating the load. The differential is mounted a little forward of the main axle. The ordinary form of bevel drive is incorporated with the differential shafts, the propeller
shaft being provided with universal joints fore and aft. Ball bearings are fitted in the differential-shaft
casing, and they are automatically lubricated, which obviates all but supervisory attention from week to week.
The final drive is by means of two internally-toothed rings meshing with small driving pinions, both the gear-rings and the pinions being constructed of nickel steel. The internally-toothed rings are, of course, effectively mounted on the rear road wheels. Perch poles are provided, the forward ends being universally mounted to the main frame members, and the rear ends utilized for mounting the rear brake shoes.
Ample braking accommodation is provided for the machine, that operated by the hand taking effect on brake drums of exceptional diameter cast integral with the road wheels. The foot-brake is located forward of the differential shaft, and consists of two adjustable castiron shoes pivoted on rocking arms. We looked round for the adjustment of this brake, and were pleased to notice that the means provided did not necessitate one's almost having to take off the body to effect the necessary adjustment.
We must give special mention to the main suspension. Remarking on the exceptional length of the rear springs, which when measured proved to be 54 ins., we were informed that a considerable number of Original Berna lorries are sold for passenger transport, and to en: sure comfortable iiding particular attention has been given to the matter of main suspension. The load-carrying capacity of the machine is a.', tons.
Initial Observations.
Just as we were completing our observations, we were notified that all was ready, and, on going round to the back of the machine, we saw the tailboard bulging out with the load, which, although not of the full capacity of the machine as far as we■ght was concerned, on account of the bulky nature of the paper rolls, suited our purpose, and weighed just upon two tons. We took the mileometer reading, which
stood at 1204 miles, unscrewed the petrel-tank cap and carefully took note of the level of the fuel, and then inquired for the engine oil overflow, and, on opening the tap, the oil just trickled out, which condition of things gave us an opportunity of noting the mileage attained throughout the day, as well as fuel and lubricant consumed. Of course, we needs must start up the engine, the ulterior object being for the purpose of noting the compression of this comparatively-longstroke unit. It proved to be particularly good.
We started away in excellent form, and the first delivery took us over a continuous series of steerOnclines as far as Tunbridge, but throughout the morning's run there was certainly little for the driver to do but steer, and, notwithstanding the stiff gradients, neither the firstnor the second gear was utilized once, Engine Flexibility.
The flexibility of the engine was emarkable, and it answered to the accelerator pedal perfectly. No matter what the state of the traffic, the Berna accommodated itself to suit all circumstances, and an interesting series of photographs, taken while running through Maidstone, will show that it was not all clear travelling so far as traffic and road conditions were concerned.
Passing through one very narrow business thoroughfare, a bulky horsed dray took up quite half the roadway, leaving a width almost a few inches short. of the track of the machine. Our driver, however, was in no way disconcerted, and rather than reverse or make a detour he negotiated the kerb with the offside road wheels, and got through without the slightest degree of fuss or undue agitation of either clutch or change-speed lever. This incident is mentioned to show the flexibility of this *ton machine.
Tonbridge was reached and the load delivered. We then ran to Tunbridge Wells, and returned to Maidstone with about. two tons five cwt. on board. It was necessary for us to deposit our return load at the railway siding at Maidstone, before taking up the load for Temple Press Ltd., and this gave us an ample opportunity to note the manceuvring of the machine at. the same time that horsed wagons were being drawn up to the railway trucks. It
interested us to notice how easy a winner was Driver Walters with the Berna, the vehicle was backed up to
the truck and a roll was being " entrained " before the horsed wagons had shunted into suitable positions to the trucks.
Before returning to Messrs. Reid's mills for the paper to be delivered to Temple Press Ltd., we pot up at the " Star and Garter," and, so far as the driver and other occupants of the cab were concerned, took on board a liberal supply of solid fuel to carry us through the remainder of the day. We arrived at the Tovil mills before 3 and exchanged our load for one—to be delivered in Roselcry Avenue--which weighed a total of two and a half tons. After getting four rolls aboard, it was found that their bulk prevented our carrying the additional two. As they were 4-8 ins, wide and each roll contained about 4521 yds. of paper, the diameter considerably exceeded that of the length, and it was therefore impossible, to do more than take four aboard, much to the disappointment of Driver Walters. We then reminded him of the fact that
it would be necessary to climb Wrotharn Hill, but this appeared to have no effect, and the hauling capacities of the Berna up this stiff incline during the journey home caused us to understand his indifference whether the machine carried three tons or five tons.
Starting for Rosebery Avenue.
We started away from the mill yard at 3.45, with, as we have said, a load of two and a half tons. A. good speed was maintained throughout the, next 38 miles travelled, the engine pulled consistently, and 'ticked over " or raced as required, immediately responding to the will of the driver. We overtook several well-known makes of motor vehicles, both starri and petrol-driven, and climbed Wrotham Hill with the needle on the speedometer registering "fully up to the legal 12 m.p.h.," and this with the hand lever in the thirdspeed notch. As most of our readers will know, this hill has a maximum gradient of 1 in 14, and it will be agreed that this is a fine performance for a commercial vehicle of this class.
Final Observations.
On our arrival in town, we first of all took the speedometer reading, which now registered 1287 miles, and this showed that we had covered in the day 83 miles. The loads and distances, properly summed, gave a total of work done reaching 192.75 net ton-miles.
The fuel consumption was the next important factor, and we mounted the driver's seat, unscrewed the petrol-tank filler-cap, and got the driver to fill the tank exactly to the carefully-observed morning level. Precisely three cans of petrol (each sealed) were emptied into the receptacle to do this, and this requirement showed that six gallons of fuel had been used in the day's run. This, it will be observed, works out at 13.8 miles per gallon. We are bound to admit that this was an exceptionally-go.od performance.
In the matter of oil consumption, we were equally well impressed; on opening the oil level and getting the driver to fill in the lubricant, a quarter of a gallon of " Gargoyle" was poured into the crank chamber. This worked out at the satisfactory figure of 332 miles per gallon of lubricant used, and we were in formed that this was quite average.
We Examine the Valves and Plug Points.
It only remained for us now to ask for one of the sparking plugs and valve caps to be removed. Driver Walters immediatelyresponded, and was soon at thekit box for the necessary tools. In less than three minutes all four plugs were removed and placed for our inspection. On examination, it was found that all these accessories were in a remarkably-clean condition, plug points and the exhaust valve, which were removed, being as dry as the proverbial bone.
Asking the driver how often he took the cylinders down, we were informed, " Oh, about once in 12 months, and that was the last overhaul I did ; I may tell you I then dismantled the whole of the engine and transmission, and made re-adjustments, in a single day.'