Snowbound
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How the Ministry of Transport and County Councils Have Built .Up a Force of Appliances to Keep the Roads Open Whatever the Weather By Alan Smith
HEAVY snowfalls this winter will not catch—or have not caught— the highway authorities. unprepared. Several thousand snowploughs and other snow-clearing appliances, strategically placed throughout the country, stand ready for instant turnout.
Less than 10 years ago, the story was different. Then came the "Ice Age" ' winter of 1946-47. Important highways were blocked for many days because there were not enough snowploughs, or those that were available were insufficiently powerful. A public outcry followed, and it was realized that a greater number of big snowploughs should be maintained because of the country's increasing dependenee upon road communications.
A Ministry of Transport committee was set up, comprising representatives of county councils and goods and passenger operators, to secure the co-operation of road users in undertaking snowplough operations. The Ministry sought suitable types!of 'heavy equipment and the Mack 170 b.h.p. six-wheel-drive petrol-engined chassis was decided upon. Numbers had been left behind by the U.S. Forces, who had actually demonstrated the efficacy of Mack snowploughs for clearing aerod tomes.
Both the Ministry and local authorities bought Macks and Ministry engineers collaborated with manufacturers on the design of high-wing plough attachments. Rescued from lonely neglect in different places, numerous Macks have passed through the Hendon depot of the Traffic and Mechanical Branch of the Ministry for reconditioning. Spares that could not be obtained were speeially made, and the vehicles have been restored and modified to take the appropriate equipment.
Reserve at Hendon
Now, the county highway authorities have a large reserve of snowploughs needed for the clearance of the roads under their control, whilst the Ministry, through its divisional road engineers, commands a force for the clearance Of trunk roads. A small number of snowploughs and a blower are kept standing by at Ilendon for use within 60 miles of London.
Of 6,600 snowploughs in England now, 156 are of the Mack type. In Scotland there are 130 Macks and 1,179 others; and in Wales 18 Macks and 290 lighter appliances. In addition there are nine snow blowers, for clearing deep drifts, and a large number of bulldozers, angle dozers, gritters and other machines. Of the Mack-s, 84 in England, 28 in Scotland and 11 in Wales are Ministry-owned, the remainder being the property of local authorities. The greater proportion of the remaining appliances mentioned is owned by local authorities. Newly added to this force are 20 more Macks, 68 trailer-gritters and a small blower. Ministry-owned appliances come under the -control of local authorities for use on trunk roads, but are maintained at • the Ministry's expense.
In their original military form, the Maas had canvas .hoods. on the cabs. In their rebuilt form they have steel cabs made in six sections and supplied knocked-down to those authorities who want them, assembly being simply a matter of seam-welding.
, There ,are two types of snowplough gear. A snowplough has to be ,capable of being raised a few inches above the road to avoid ploughing the surface itself or ripping up cat's eye studs. One type is elevated mechanically and the other hydraulically.
With the Johnson mechanical gear there is a sub-frame suspended beneath the chassis of the Mack for about threequarters of its length. It hangs from the front on a large triangular trunnion and at the rear on two substantial brackets. At the front of the sub-frame is a simple windlass, therope from which attaches to the plough. Whenever the height of the blade has to be adjusted, the windlass is turned.
The plough is 11 ft. wide, 7 ft. high and resembles the bows of a dreadnought. It weighs over 12 cwt. and runs on caster wheels, so that the subframe takes the stresses of pushing it through the snow rather than supporting it and the weight of snow.
When travelling long distances to the scene of operations, the plough is carried in the body of the Mack. The plough is bolted to the front of the sub-frame with the aid of a gang of men and a mobile crane.
A mechanically adjustable plough is free to move up and down when in use, hut a hydraulic type is rigid. Adjustment can be made, however, without alighting from the cab. The Cuthbertson hydraulic equipment is supported on a braced vertical frame attached to the front of the chassis, and there is a vertical hydraulic cylinder and ram. The plough is 9 ft. 6 in. Wide and 9 ft. high.
Normally a snowplough operates with the blade set 2.in. from the road surface. Seeds of 15-20 m.p.h. are maintained, although the condition of the snow affects ploughing technique.. Soft snow needs to be ploughed at 25 m.p.h. to prevent its passing under the blade. Drift S some 10. ft. deep have been tackled in Scotland, where a few Mucks have been .equipped with twoway radio. When ploughing, a Mack may consume two gallons of petrol a mile. Fuel-tank capacity is 63 gallons: Ploughing High Snow
It is possible to plough through snow that is higher than the vehicle beeause the blade undermines the pack, so that it collapses. It does not fall over the vehicle. As the front •iif the blade is about 9 ft. from the cab, the /steering wheel has to be accurately con-: trolled, for a slight wheel movement can veer the blade appreciably.
Often a way has to be ploughed across territory so deeply snowed that only the telegraph Poles indicate the line of a road. Where such conditions are likely to occur; the telegraph poles now bear tags on which are inscribed numbers indicating the distance in feet that the poles are from the carriageway.
Originally the Macks had bold-lug cross-country tyres, but as snow packs between the bars this type of tyre is no better, for snowplough -work, than the normal road cover. New tyres which have been made by Dunlop and India are of the ordinary road-tread pattern, to which Chains are fitted. Tracklaying vehicles are used for certain purposes, although slower than wheeled types.
The latest development at Hendon has been to build snowploughs which carry their own gritting equipment. Normally a lorry follows .a snowplough to distribute grit, or a small trailergriller may be towed. Sixty Macks that have been modified at the depot in recent months have Atkinson 7-cu.yd. bodies of the kind similar to that make of lime-spreader.
There is a hopper body with a moving belt at the bottom to 'pass the grit through an adjustable gate. From this the grit drops on to two spinning discs which distribute the material across the path cleared by the plough.
The most spectacular appliances are the snow blowers. These are based upon Diamond-T and F.W.D. chassis and each has an enormous sixcylindered auxiliary engine with 6-in.dianteter pistons and primary drive by IS matched V-bel t s. Ibis engine eccupie.s the whole of the length of the eliassis aft of the cab. Starting equipment is 6 v.
The blowers are of the U.S. Bros type. A shalt disposed under the front . of the chassis takes the drive from the V-belts to a differential. Shafts from the differential rotate 3-ft.-diameter discs at L200 r.p.m.
These discs tate radial vanes and there are various kinds for use under different conditions of snow. Snow is impelled by the vanes through Chutes which can be adjusted to discharge to . either left•or right.
The discs are used with soft-iron shear pins which will break if a hard foreign body is Struck. Sturdy steel VAnembers,act as small-scale ice-breakers, in which function they are supplemented by rotary flails.
In action, the noise of a snow blower is impressive and the heat given off is unseasonal. Hails and discs churn found in monstrous anger and twin ninnies of snow. spurt 20 ft. into the air. A notice carried on the appliance says: " Keep Clear."
These vehicles clear a lane 10 ft. wide but their use is restricted to the open 'country. Smaller British-made Bros blowers are mounted on a Ferguson tractor and a Land-Rover. It is under.: stood that a big British blower is now iii production.
Frequent Inspection
Ministry vehicle examiners inspect the snow-clearing appliances twice a year, repairs being performed at I tendon.
The men who drive the snowploughs are grand fellows, who like the job because of the challenge it presents.. Not everyone would care to concentrate for hours on end at the wheel, carving a lane through a dense fall, perhaps to find on the return run that a drift has blocked the way back to base. But there may be compensations in the generosity of the receptions invariably given by villagers isolated for many days until a siuraplough's arrival.