Steam Vehicles at the Show.
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MESSRS. JAMES ROBERTSON AND SON, of Dock Street Engineering Works, Fleetwood, exhibit one of their standard 5-ton hydraulic tip wagons, fitted with Stagg and Robson wheels, which are descrilwl elsewhere in this report. The steel frame is of channel section, 5*in. by 2-01. by 7-16in., and carries a substantial body, having a capacity of 5 cubic yards. The tipping gear is operated by a hydrau• lie cylinder and ram, supplied by a suitable valve on the auxiliary steam pump, the whole arrangement being worked from the drivel's seat ; the water so circulated is returned to the tank when released for the lowering of the body. The boiler is of the fire tube type, with all the tubes arranged radially between the central firing shoot and the outer annular passage which leads the fire gases to the funnel. There is no clinkering door, and the fire-bars and ash-pan, which are slung by wire ropes, can be raised and lowered as required, the whole base of the boiler cover drawing up on vertical pins which give a firm lock. The feed heater has a filter at the base, and no condensed water drops on the road, all being returned to the tank, which is a point of importance in frosty weather. All the boiler tubes are submerged, and steam is led off through an anti-priming pipe to a compound horizontal engine, of the enclosed type, with cylinders 4in. and pin. diameter, by sin. stroke. A unique system of small aluminium casings, which are instantly removable, prctects the piston rod and pump glands. All the gearing is exterior to the engine casing, and consists of a slid.
ing, double steel pinion on the crank shaft extension, which is engaged, at the driver's will, with either of two toothed wheels on the second motion shaft. This shaft also carries the differential and two chain pinions, one at each end, from which the transmission is carried by Hans Renoid roller chains to sprocket wheels
bolted to the fellocs of the 3gin. driving wheels, the two ratios provided between the engine and rear road wheels being to to s and 17.8 to I. The hack axle is of the composite type, all but the arms being of 11 girder section steel, 6in. by 4iin. The ends are mild steel forgings, solid forged, and slotted Out to fit the girder, to which they are riveted, the arms being turned up to fit the bushes of the wheels. The rocking front axle is guided in steel horn plates, a transverse, inverted, laminated spring being used to carry the weight from a central point to its ends.
THE ST. PANCRAS IRONWORK CO., LTD., 171, St. l'an eras Road, N.W., show a 5-ton wagon, with bent rail side. The frame is of channel steel, sin. by 21in. by +in., and carries a boiler of the vertical fire tube type, with straight tubes and top stoking. A special form of rocking fore-carriage is employed, with a central pivot both fore and aft of the boiler, coupled up to both ends of the front springs, which gives a great freedom of movement, as will be seen from the illustration. The engine is a compound horizontal, with cylinders din. and yin. diameter,
by bin. stroke ; a piston valve, fitted with T.ancaster's patent packing in the shape of rings, in order to reduce any leakage to a minimum, is used in the high-pressure cylinder, and an ordinary balanced slide valve is used in the low pressure cylinder. The feed pump is driven off the crank shaft through reduc•-• lion gear, and an injector is also provided. The crank shaft carries a single pinion, which transmits the power to the intermediate shaft, upon which are two sliding pinions ; these engage in turn with two spur wheels on the differential casing on the third motion shaft, which has a chain pinion at each end, Hans Renold roller chains taking the final drive to the rear road wheels, which are cast steel and of Krupp's manufacture. The whole transmission is in an oil-tight casing. The arrangement to lock the differential is by the insertion of a pin through one of the chain pinions. in one of four positions. The back axle is of square section, 31in. thick, forged from a steel billet. The whole of the bearings throughout the machine are of phosphor-bronze, as also are the bushes of the road wheels. The tare weight of the machine on view is 4 tuns 16cwt., and the builders are able to turn out a special steam "float," in which case the back axle is cranked, so as to have a length of fift, behind the engine casing, and to have the deck of the well only i8in. off the ground. This design has been found very useful for safe makers, or for dealing with heavy machinery, electric cables, plate glass, masonry, and other heavy articles of comparatively small bulk.
TIIE THAMES IRON WORKS SHIPBUILDING AND ENGINEERING CO., LTD., of Greenwich, enter the field with a 4-ton lorry, which embraces several novel points in its design. The unique feature i.; the placing of the engine transversly, the pinions on the crank shaft engaging with a longitudinal shaft and universal coupling, which transmit the power to the live back axle in a manner similar to the general practice of petrol motorcar design. The frame is of channel steel, 6in. by 21in. by Sin., carrying a boiler of the locomotive type, and the suspension includes a central support between the front springs. The engine, which normally runs at 500 revolutions,. is a compound horizontal, having cylin
ders in and 6in. diameter, by 6in. stroke, with balanced slide valves, and is. enclosed in an oil-tight casing, as also are
the whole of the gears, which are machine Cut throughout. This method of hanging the engine makes it exceptionally easy of access should it be required to take off the cylinder heads or to examine bearings, big ends, or connecting rods. The change speed lever is alongside the engine casing, but the ether control levers arc beside the driver, who has all the syphon lubricators under his seat in two boxes, where he can conveniently regulate the lubrication to any particular bearing. The bevel drive and compensating gear on the live back axle are enclosed in a cast steel and aluminium cover, and the road wheels are weight of the machine is 3 tons recwt., and it has been employed for several months in the builders' own service. Two brakes are provided, in addition to the reversing power of the engine, one of the screwclown pattern on each driving wheel, and the other operated by a foot lever to a drum on the second motion shaft. An exceptionally large water tank is fitted, with a capacity uf_ re5 gallons. This machine is a compromise between the accepted designs of steam wagons and petrol cars as regards general arrangements, and the result shows that much may be done to combine the two practices.
MESSRS. WALLIS AND STEEVENS, LTD., of North Hants Iron Works, Basingstoke, Hants, are exhibiting two of their tractors, one with a single cylinder of eine diameter by gin, stroke, the other is a compound engine of 4in. and 8*in. diameter, by gin, stroke. Both boilers are, of the locomotive type, with the engine and gearing mounted on the top of the boiler plates. In the new design the engine runs in an oil bath, which is a distinct improvement as regards protection and wearing qualities. The boiler of this machine is larger than usual to furnish sufficient steam for the increased calls of the engine, which is designed to haul a 7-ton load, compared with a 5-ton load by the smaller tractor. There are on the crank shaft two cast steel pinions, which alternately engage with two large cast steel spur wheels on the second motion shaft. This is carried across the rear end of the boiler about 6in, above the top of the firing doer. On the end of this shaft, remote from the spur wheels, is a cast steel pinion, which engages with a large spur wheel hotted to the outside of the differential on the sleeve of the live axle. The wheels are of the traction engine type, with broad strakes and narrow spaces between the same to comply with the recent regulations, and the tare weight is 4 tons ticwt., or gewt. below the new limit. A feature which all visitors should examine is the Wallis patent damper, which is arranged in the smoke-box to cover all the small smoke tubes when the • tractor is standing. At such times only three " by-pass " tubes of large diameter are available fur the passage of the fire gases, whereby the fire is kept going, but practically no steam is generated. The control of this damper is entirely in the hands of the driver at all times. It will be remembered that Messrs. Pickford are making a large use of these tractors in London.
MESSRS. SAVAGE BROS. LTD., of Si. Nicholas Works, King's Lynn, exhibit one of their 5-ton steam lorries fitted with water tube boiler, although they are prepared to supply a locomotive type of boiler if necessary. A long cylindrical steam chamber is carried to the right of the funnel and combined with the main regulator valve, whilst a water heater has been recently introduced into the design. The machine has a level goods platform and metal wheels with tee-pieces which have the tread and semi-disc spokes riveted to them. The pump motion is partially enclosed, but is outside the engine casing; and an attempt has been made to encase the chain drive. The en gale is a compound horizontal with cylinders 4in. and yin. by sin. stroke, arranged to run at a normal speed of 450 revolutions. The engine casing contains the second motion shaft in addition, and the transmission is by chain from the compensating gear shaft to sprockets on the driving wheels, which are 3 feet diameter. The tare of the machine is 4 tons iscwt. complete, some weight being saved by the use of only the one counter shaft, which also carries the compensating gear.
MESSRS. E. S. IIINDLEY AND SON, of Bourton, Dorset, and is, Queen Victoria Street, ac., show a 4-5-ton lorry, with channel frame, 6in. by zlin. by *in. The boiler is of the locomotive type, but stoked from the top, and accessible all round, the barrel being very low and all the tubes submerged. The front wheels are of cast steel, and the driving wheels of the traction engine type. A horizontal compound engine is used, the cylinders being 4in. and 6in. diameter, by yin, stroke; the second motion shaft is partly inside the engine casing, and carries the sliding gears on an extension borne in a bearing from the right-hand channel. These pinions, which are between the flywheel and the engine bed, engage one or other of two spur wheels, which have a double helical pinion between them, to drive upon the double helical wheel on the differential casing on the live back axle. Adjustable plate radius rods are employed. Two shoe brakes are provided for the rear wheels, and a central metal bar is used as a brake by forcing it against the revolving back axle. These machines are capable of maintaining a steady six miles an hour under full load in give and take country.
THE BRISTOL WAGON AND CARRIAGE WORKS CO., LTD., of Lawrence Hill, Bristol, exhibit one of their Standard 5-ton tip wagons, having a channel frame 5in. by 310. by gin. The wagon on exhibition is fitted with a Balmforth boiler, a specimen of which is staged on another stand in the Exhibition, but other types are supplied to order, including the locomotive design. No automatic pump is employed, ths feed being supplied by a Moore steam pump, with the alternative of an injector. A horizontal engine, having cylinders gin. and yin, diameter, by yin, stroke, is employed, one cylinder
being on each side of the frame. Sliding cut steel pinions are on the crank shaft, and transmit the power to the single countershaft, which carries two cut steel spur wheels. The drive to the live back axle (in. diameter) is taken from this countershaft by a double Brampton roller chain of ziin. pitch. The driving wheels are 42in. diameter, with tyres rein, wide, and the machine has a tare weight of 4 tons rocwt. aqr. Practically no alterations have been made in the construction of this vehicle, which is exceedingly stout throughout. The tipping gear is conveniently arranged for discharging the contents of the box body, and the front axle is pivoted at the centre with double cross springs.
THE HERC:CLES MOTOR WAGON CO., of Levenshulme, Manchester, show one of their standard 5-ton wagons.with level platform, which can be conveniently tilted. The frame is of channel steel, 5in. by akin. by tin. The boiler is placed with its centre about four feet back from the dash, and the driver's seat is somewhat to the front of it. It is of the vertical smoke tube design, and arranged so that the whole of the tubes are submerged. The fire gases travel in their passage to the funnel • up vertical smoke tubes and then through diagonal tubes connecting the top combustion chamber to the casing which surrounds the upper portion of the boiler. The engine is of the compound horizontal type, with cylinders kin. and yin. diameter, by fiin. stroke, and is enclosed in a dust-proof casing to run in oil. This casing contains also the second motion shaft and the compensating gear, which last shaft extends each side from the casing to the brackets carrying the chain pinions in brackets from each side of the frame. The back axle is curved and of square section, being 3tin, thick ; and the springs mounted upon it are of the laminated type with auxiliary bumping springs. The other axle is on Perkins' Oscillating system, with a view to taking distortion from the frame, and is different from other rocking front axles in that the wheels travel up and down vertically, whereby the tyres get a full bearing on the road, whilst the lift of the frame is very slight. The wheels are of the composite pattern with cast steel centres, and the special feature is that the ring on the inside of the felloe is turned over the wood so as to distribute the pressure over the whole face. The driving wheels are 3gin. diameter with tyres loin. wide. There is also exhibited on the stand the Perkins' patent automatic relief valve, for draining the cylinders ; this is worthy of inspection by all interested in steam haulage. The wagon is well finished throughout, and is the outcome of extended tests made by Mr. Perkins under all road conditions for over seven years. MF.SSRS. FODENS, LTD., of Elworth Works, Sandbach, exhibit two of their standard 5-ton steam wagons, one of which is a repeat order for Messrs. Mark Mayhew, Ltd., of Battersea Flour Mills, S.W., and the other a repeat order for Messrs. Bowron Bros., of Crayford Leather Mills. The main frame of the vehicle has channels Gin. by sin. by din., these being brought nearer together towards the front of the boiler, which is riveted to the two side members and the fire box shell by brackets. The compound engine, with cylinders kin, and otin. diameter, by yin. stroke, is mounted on the top of the boiler, forming a steam dome, and the balanced crank shaft, which has keyed-on sheaves, is carried in bearings in the top of the firebox sides. A double steel pinion slides on four feathers on an extension of the crank shaft, and is controlled by one lever. This pinion meshes with one or other of two phosphor-bronze spur wheels, carried on a stud shaft, with one central bearing about rein, long, giving the high or 1,-Nw gear ratio. Between these two spur wneels is the chain pinion wheel, from which the power is taken by a Hans Renold roller chain of zfin. pitch to the compensating gear on the live back axle, which is solid forged from a billet and 4tin. diameter. High-pressure steam can be admitted to the low-pressure cylinder by a separate three-way cock, which provides a double exhaust for working out of any difficult place. The saving in weight which has recently been effected by Messrs. Fodens amounts to about 3ocwt. It has been secured by reducing the weight of the boiler some 5cwt., and taking another iscwt. out of the horn plates and wheels, which are now of cast steel, with the spokes and running strips hydraulically riveted to the tee-ring. The previous practice was really much heavier than was necessary for the load that was carried. A large water tank runs from the rear of the foot plate to within 18in, of the back of the frame, and holds 170 gallons of water, which is enough for 20 miles on fair roads. Recent improvements by :Messrs. Fodens include casing in the steering worm and wheel to protect it from mud; introducing small coil springs in the joint links which control the steering axle in order to reduce vibration on the brackets, and to avoid back lash; using slides to carry the ends of the inverted laminated spring to save wear on the top of front axle ; making all the en gine parts to standard and interchangeable; fitting a large band brake on the
rear axle, with deep wooden blocks bearing between flanges, and having light side guide plates bolted on to prevent their getting out of truth on the surface of the drum, the whole being of ample surface. The tare is several cwt. below the legal limit, and Messrs. Fodens have no difficulty in complying with the requirements of the registration authorities, whilst the fact that they have found it necessary to make so few changes in their general design, apart front weight, speaks well for the value of their road experience for the production of heavy motorcars.
MESSRS. MANN'S PATENT STEAM CART AND WAGON CO., LTD., of Pepper Road Works, Leeds, exhibit one of their improved type of 5-ton steam wagons and a new type designed to carry two tons at eight miles an hour. The first-named of these is generally well known ; but we may draw attention to some recent improvements which we notice. The boiler is somewhat reduced in length and in. creased in diameter, though the heating
surface has been increased, which enables the driver to see the ground in front of him better than before, whilst the barrel and shell sides are made in one plate ; it can be lifted out of the frame for repairs. The first motion gearing shaft, which previously ran in a separate casing, now runs in the engine oil bath, which is placed lower than before, so that it is possible to get at the engine without tilting the platform. The automatic pump is driven
from the second motion shaft, instead of being driven direct from the crank shaft, and the original method of bolting two concentric wheels together, which was the method employed to render legal a 4-ton tare under the old Act, has been replaced by ordinary single driving wheels, with tyres loin. wide. The second machine is a single cylinder, in order to get a minimum of working parts, the diameter being 41in. and the stroke 6in. Tt has an in
teresting appearance, the footplate being only 18in. from the ground. The crank shaft carries a case-hardened, mild steel pinion, gearing into a cast steel wheel (with teeth cut out of the solid) keyed to the intermediate shaft, upon which are the pump eccentric, drum for foot brake. fast and slow main driving pinions, and friction clutches for same. The spur wheel on the live back axle is double, to mesh with the fast or slow speed pinion. Metal friction clutches with smooth faces, are used in the transmission on a squared portion of the second Ince tion shaft. The control is by one lever, the speed change being effected without stopping the engine. The foot brake acts upon a large drum on the intermediate shaft, and is sufficiently powerful to hold the engine on a steep gradient. It is accordingly possible, when the wagon is hindered or stopped by traffic, even on a hill, to use this brake, while the engine continues to run for the purpose of pumping water into the boiler so as to avoid blowing off steam. No injector or donkey pump is used. The engine and first motion gearing work in the same oil bath, as for the larger type, and special equalising gear is provided to keep the main axle and intermediate shaft parallel to one another. The back wheels are 4oin. diameter, and thi springs are below the axle.
THE YORKSHIRE PATENT STEAM WAGON CO., of Vulcan Works, Hunslet, Leeds, were unable to hold back delivery of the wagon for the Poplar Board of Guardians, to which we referred in our forecast. The 5-ton wagon which is exhibited has a channel frame of 5in. by shin. by iin., well braced and stayed, which carries at the fore end, placed transversely, the firm's special design of smoke tube boiler. This boiler is stoked through a fire door, and is built in two horizontal sections. The fire gases pass from the centre outwards through one series of tubes, and travel back from the two end smoke spaces through another series of tubes to the upper side of the dividing plate, being assisted in the return by small individual blasts from the exhaust which are delivered into each of the upper
set of tubes. One cylinder is carried on each side of the frame, and each is encased in an oil-tight cover, the dimensions being 4iin. diameter for the high pressure, and plin. for the low pressure, by Ain. stroke. The feed pump is driven direct from the crank shaft, and an injector is fitted in addition_ The crank shaft carries two separate cut steel pinions, sliding on a square. These engage in turn with corresponding cut steel spur wheels on the second motion shaft, which carries at the extreme right side another pinion meshing with the tooth wheel outside the differential on the live back axle. The whole of the transmission in the new design which is now ready is enclosed in a dustproof casing, and runs in oil, which is an improvement that has been effected during the last 13 months in this wagon, and is of very great value in practical work. The back axle and shafts are of mild steel forgings, the first of these being 41in. diameter, The road wheels are Stagg's patent artillery type, a number of which are ex
hibited on the stand, and will repay examination. The driving wheels are 3gin. diameter by rotin. wide, the steel tyres being I.in. in thickness. The tare of the machine is well within the new 5-ton limit, and there is still a margin for the extra weight to be availed of if needed for special purposes.
THE SEAHAM HARBOUR ENGINE WORKS, of Seahain Harbour, Durham, show one of the most recent 5-ton machines put on the road by the Marquis of Londonderry's Engine Works. It is No. 35 on the firm's books, and differs greatly from their No. it. The frame is of steel channel 6in. by sin. by sin., and the total length of the vehicle is left. The original type of water-tube boiler, with two narrow rectangular boxes connected by inclined tubes, has been given up in favour of one of the central fired vertical smoke tube type. This type of boiler has been found, over a period of 14 years, to cost so per cent, less in upkeep than the locomotive type, according to the records kept for each class of boiler at Lord Londonderry's works. The feed water is delivered by a coil pipe in a chamber through which the exhaust steam from the engine passes. The original type of double high-pressure engine, with two 4in. cylinders and a 6in. stroke, has been replaced by a compound engine of 4fin. and pin. diameter with the same stroke as the earlier type. The older engine was found insufficient for work in a hilly district. The locomotive type of slide valve and salve gear is employed. The original gear drive has been adhered to, with slight modifications. The arrangement of the shaft brackets consists of two frames of cast steel, the crank-shaft and intermediate shaft revolving in brass-bushed metal balls, free to swivel, to counteract any tendency of the shafts to bind at the necks when the vehicle is running over a rough surface. The change-speed wheels are carried outside the engine casing on the crank and intermediate shafts, and the main driving pinion'is on the latter. The teeth are machine-cut on the crank and second motion shaft, the former of which is sin. and the latter 310. diameter. The main driving pinion engages with the spur wheel of the differential on the live hack axle, which is 41in. diameter and carried in two cast steel axle boxes dined with phosphor-bronze) which are free to slide in slots in the side frames. Both axle boxes and slots are machined
to a ralius struck from the centre of the intermediate shaft, so that the distance between the centres of that shaft and the main axle cannot vary more than I-32in. The road wheels have wooden spokes of a specially curved design, and the running tyre is pressed on and bolted to the inner rim, their appearance striking one as somewhat similar to the chariot wheels of the ancient Romans. This machine is sister to the one which travelled from the North to London, a distance of 300 miles, in June last year, occupying 54 hours from point to point, when the large capacity of the water tank (22o gallons) was found very useful. The firm's London representative, Mr. Arthur E. Harrison, Sea. ham Wharf, Nine Elms Lane, Vauxhall, S.W., informs us that three new wagons have been registered since March 1st.
MESSRS. JESSE ELLIS, LTD., of Invicta Works, Maidstone, show their new type of steam wagon, with a locomotive boiler, which has a hinged ash pan con\rolled by worm gearing, and no fire door. the most interesting point about this boi\sr is a special arrangement to stoke from the top down a central shoot, instead of by the usual fire door on a level with the driver's knees. Another modification is that the safety valves discharge into the firebox instead of up the funnel, an that when the machine is stopped by traffic the blowing off difficulty is not worsened by additional blast from the safety valves. The engine is of the compound horizontal type, with cylinders din. and sin. diameter, by 6M, stroke, with balanced slide valves, and is enclosed in an oil-tight casing, through which the extension of the crank shaft passes, the extreme end being carried in a long bearing and supported by a bracket to the frame. This projection of the crank shaft carries two cut steel pinions, and a short lever to move them on the square. One or other of them engages at will with two spur wheels on a short enuntershaft carried in two brackets, the length of this second motion shaft being only 2ft. The drive is then taken by a pinion on the second motion shaft to a toothed wheel on the differential sleeve on the live back axle, which is 4in. in diameter, salid forged, and in roller bearings. An interesting feature is the use of Stevens's patent shaft to keep the countershaft
and back axle in parallel. This shaft runs the whole width of the lorry, being carried from the frame in bearings just forward of the rearmost end of the back springs, and has connected to it at each end a short, horizontal arm and a double vertical link, fastened to lugs on each of the radius rods. The object of the device is to keep the gear wheels evenly in mesh, and it is particularly applicable to a single frame machine of this design. The driving wheels
are cast steel, and in one piece, with grooves in the tread, which give the wheels a smooth surface although they have the appearance of bearing riveted sections. The tare of the machine is 4 tons iscwt. sqr., including the body, which has removable side 5,
MESSRS. WILLIAM FOSTER AND CO., LTD., of Wellington Foundry, Firth Road, Lincoln, who have been building single-cylinder tractors for some years, have added those of the compound type
to their manufacture. One of these new tractors, with cylinders 41in. and Sin. diameter, by gin. stroke, is exhibited. The boiler is of the usual locomotive type, with main. iron tubes, and works at a pressure of sloth, on the square inch,. which should result in great economy with a boiler of this class. Extra water tanks are disposed on each side of the forward end of the boiler, which carries the cylinders and stop valve on the top in the usual way, the dome serving as a steam jacket. The engine has slide valves of the Stevenson type, and a Pickering governor is fitted for stationary work. The crank shaft is carried in bearings slin. diameter by gin. long, and two pinions are held by four solid keys forged with the shaft and machined on it. Power is transmitted from this shaft by sliding cast steel pinions engaging spur wheels on the right side, with a cross shaft to the near side, where another pinion meshes with the large spur wheel on the live axle. The driving wheels. are 4ft. 6in. diameter, by gin. wide, and are built up in the ordinary way, with a tee-ring and diagonal strips, the inner face. of the rims being turned to receive the brake blocks. It should be noted that the engine is fitted with an extra wide tender. arranged with two seats, so that the driver can attend to the stop valve while the. stoker controls the steering gear in close traffic. Large gravel boxes are fitted on each side of the tractor in front of the driving Wheels, and the shutters work effectively to open and to close the shoots. from these boxes. The machine weighs, 4.1 tons, has a hauling capacity of 8-ro tons on a level road, whilst it has taken as much as Ei tons up a gradient of i in ro. During a recent test in the neighbourhood of Lincoln, with a load of 7 tons, a distance of 16 miles was covered in slightly under three hours, which shows that the full legal speed can be maintained without difficulty under full loads.
MESSRS. RICHARD GARRETT AND SONS, LTD., of Leiston, R.S.O., Suffolk, enter the ranks of exhibitors of motor wagons for the first time, except at the December Cattle Show, with a 4-5 ton vehicle. The system embraces several novel features, which are combined with solidity of construction. The main frame is of channel section, 51in. by sin, by
gins with four cross stays of lighter channets bolted to the top of the main channels. Diagonal plates are used to strengthen thp rear end where a stout trailer bar is well provided for. A. vertical fire. tube boiler is fitted, the shell being Welded and a butt strap riveted on the outside. Central stoking is employed, and this tube is also welded. The drying coil, smoke-box top and funnel come away together by the removal of only three nuts. The automatic pump is driven from the differential shaft and does not feed when the lorry is at rest, at which times the injector must be used. The engine is a compound horizontal, with outside valve chests, the cylinders being 3in. and pin. diameter by Elfin. stroke. A piston valve is used for the high pressure and a slide valve for the low pressure, whilst simplicity has been aimed at by doing away with the ordinary arrangement of unit motion and introducing a gear reverse similar to petrol car construction. This is absolutely unique. The crank-shaft is of cast steel, with eccentric sheaves cast on it and the crank discs bolted to flanges. The engine casing is unusually large and contains two countershafts, the second of these carrying a planetary differential. The engine cat ing, which is of unusual length, encloses all the driving gear except the chain pinions and the Hans RenoIsl roller chaina, these taking the drive to the rear wheels. The wheels are made of cast steel, the back ones being aain. diameter by gin, wide. Shoe brakes are fitted on the driving wheels, also infernal expanding brakes, and a glass water gauge is outside the tank. The control levers for the driver are arranged in the middle of the seat to be worked by his left hand ; inclined wheel steering is fitted similar to the ordinary motorcar in general appearance. Visitors should examine the controller cylinder which is part of the Garrett wagon. The first position of the lever gives both cylinders high-pressure steam ; the second position lets the engine work compound ; and the third position closes the exhaust from the highpressure cylinder, which takes the place ef the reversing action of link motion for the purpose of braking.
MESSRS. J. STEWART AND SONS, LTD., of 22, Miter Street, London, E.C., exhibit a 5-6-ton steam lorry, with a channel frame 6in, by ain. by din. It is fitted with a vertical boiler of the fire tube type and a feed water heater. The engine is a horizontal compound, with cylinders sin. by 61n. diameter, by yin. stroke, the pump being geared down from the crank shaft, whilst the engine can be run free. A piston valve is used on the high-pressure cylinder, and a D slide valve on the lowpressure cylinder. The cylinder lubrication is by a steam fed lubricator. The engine casing contains the single additional shaft to the crank shaft, which also carries the differential, the whole being enclosed in an oil-tight cover. There is a cut steel double pinion sliding on a square on the crank shaft, which engages at will one of the two cut steel spur wheels on the second motion shaft, and only the chain pinions are exposed, the final drive being with Hans Renold roller chains of sin. pitch. The use of only one countershaft is designed to save weight, and the differential can be locked from the driver's seat without difficulty. This shaft is carried in spherical bearings contained in brackets attached to the frame at each end. Special notice should be taken of the flexible drive to the rear road wheels, which are of cast steel and of Stagg's make. The chain sprockets are bolted to lugs specialty provided on the rim of these wheels, and the internal arrangement of these sprockets comprises four pairs of spiral springs.