OF A

"MARSHALL"

New Standard Road Roller

Class "S" Series with Piston Valve

SINGLE CYLINDER TYPE.

Every component, including the Boiler, is made to strict standard gauges and templates. Absolute interchangeability is guaranteed. Eventual replacements can be made Without the necessity of chipping, drilling and fitting to suit individual requirements. New parts from stock will drop accurately into place. Mechanical exactitude renders bedding unnecessary.

This exceptional facility for roadside repairs and replacements is an invaluable one, both as regards the minimum of time occupied and the ease and precision with which the work can be done in the case of accidental breakdown away from repair depots.

The engine to have a steam-jacketed Cylinder made of a suitable mixture of cast iron, of as equal a thickness as possible to eliminate cooling stresses, and as hard as can be satisfactorily tooled. The working barrel of special hardness, to be cast separately, tightly pressed into the main casing and truly bored.

The Balanced Piston Valve to be of cast iron, perfectly turned, and fitted with cast iron spring rings ; the whole working in a liner having the ports accurately tooled before pressed into the cylinder body.

The Starting Valve to he of cast iron, and placed at the top of the cylinder to ensure a dry steam supply. The Cylinder to be fitted with Automatic Drain Cocks controllable from the footplate, a Mechanical Oil Pump of our latest design for lubricating the cylinder interior surfaces, and a double Safety Valve of the "Ramsbottom" type.

The cylinder body and covers and the steam chest cover to be heavily lagged with non-conducting composition to prevent heat loss by radiation, and neatly encased with sheet steel.

The cylinder casting to be planed on its base and readily erected on a steel fixing with planed face.

PISTON AND PISTON ROD

The Piston to be made of cast iron, turned to fit the cylinder, and fitted with cast iron spring rings of the "Ramsbottom" type to ensure steam tightness. The Piston Rod to be of steel with tapered ends, firmly attached to the Piston by steel nuts and to the Crosshead by steel cotters.

The Stuffing Box for the piston rod to be provided with special metallic packings of the "Labyrinth" pattern, which remain steam-tight without soft packing and need no attention when working.

CROSSHEAD AND GUIDE

The Crosshead to he of the "Marshall" special design, made of the best malleable cast iron provided with large adjustable slide blocks of cast iron and fitted with a steel gudgeon.

The Crosshead Guide to be of cylindrical design, accurately bored to receive the slide blocks and to afford ample bearing surfaces.

CONNECTING ROD

The Connecting Rod to be of the best hammered wrought iron, turned and polished and fitted with large adjustable gunmetal bearings at each end.

CRANKSHAFT AND BEARINGS

The Crankshaft to be forged and bent out of a solid steel bar, truly turned and polished.

The Crankshaft Brackets to be made of semi-steel. The Self oiling bearings to be made of gunmetal, and to be adjustable. The oiling rings to be of the continuous-acting type, ensuring perfect lubrication and easy running, effecting considerable economy in oil, and requiring minimal attention.

FLY WHEEL

The Fly Wheel to be of the solid disc pattern, truly turned and keyed to the crankshaft ; of ample width for driving machinery by belt and prepared to receive an extra driving pulley when required.

ECCENTRIC

The Eccentric to be made of cast iron, fitted with adjustable eccentric strap and connected to the Radial Gear by forged mild steel eccentric rod with T ends.

"RADIAL" TYPE LINK MOTION REVERSING GEAR

The Link Motion Reversing Gear to be of the "Radial" type, in accordance with our latest practice. All Joints to be fitted with hard steel bushes. All pins to be deeply case-hardened. A suitable reversing lever and quadrant with notch plates to be arranged at the footplate. All rods to be steel forgings. The advantages obtained with this Gear are a reduction in the number of working parts and joints, as only one eccentric sheave, one strap and one rod are necessary; a greater area of bearing surface is given in the slides as compared with the ordinary slot link die ; an improved steam distribution is obtained which is practically equal at both ends of cylinder.

This gear is correctly designed to ensure the highest economy in the use of the steam.

No extra charge is made for this valuable improvement.

BOILER

Excellence of design, accuracy of construction, highly-skilled workmanship and expert supervision, together with the employment of specially functioned machine tools, ensure the finest class of boiler making believed to be unequalled by any other boilers of this type.

The engine to be mounted on a high-class Boiler of our latest Locomotive Multitubular type, constructed throughout of the best selected Siemens-Martin mild steel plates, and fitted with best quality boiler tubes. The longitudinal seam of the boiler barrel, and the junction of the barrel with the firebox to be strongly riveted, and special double-riveting to be applied to the horn-plate seams. All plates to be planed on the edges. All holes to he drilled. Riveting to be done by our special machinery for this purpose. Boiler tubes to be carefully expanded in the tube plates.

The Firebox. Its sides to be strongly stayed and the firebox crown to he of our patent cambered type whereby roof stays and suspension bolts are abolished, and every facility is given for the cleaning of the crown plate.

Other advantages of our patent fire-box top are:-

Great Constructional Strength. Light Weight. Perfect Water Circulation. Increased heating surface and consequent increased evaporative capacity. Established Economy in Coal Consumption. Special shape retards formation of scale.

The Boiler Front Plate to be reinforced by a steel T section stiffener. The Smoke Box Tube Plate to be strengthened by a transverse corrugation. These constructional improvements, in conjunction with the patent Firebox, form an unique combination which is unexcelled in efficiency by any other design on the market, and also offer an unequalled interior freedom for cleaning.

The front end of the boiler to be fitted with a strong flanged ring. The ring to be riveted to the boiler barrel and machined to form a perfect joint with the fore-carriage casting.

A strong steel hinged door to be provided in the fore-carriage to give access to the boiler tubes.

The boiler barrel to be covered with extra-thick fire-resisting non-conducting material, overlaid with wood laging, and neatly encased with sheet iron. Polished metal bands to be fitted round the barrel to secure the lagging.

The boiler throughout to be of ample strength to withstand the working pressure, and to be tested by hydraulic pressure before leaving our Works.

BOILER FITTINGS AND MOUNTINGS

The Boiler Fittings comprise a steel chimney with polished metal top, firedoor with air regulator, ash-pan with two draught regulating doors, set of fire bars, safety fusible plug screwed into firebox crown, Manhole Cover, Mudhole Covers and Filling Plug.

The Boiler Mountings to include two sets of gunmetal asbestos-packed Water Gauges with guards, or one set of asbestos-packed Water Gauges with guard, and two Test Cocks ; Blow-off Cock, Steam Pressure Gauge, Steam Jet Cock, Two Feed Check Valves (with Stop-Cocks interposed between check valves and boiler, so that the check valves can be examined whilst the boiler is under steam), and Harmony Signal Whistle.

TENDER

A strong flanged steel Tender, constructed of plates of adequate thickness, to be rigidly bolted to the extended horn plates of the boiler firebox ; the lower part of the tender below the foot-plate to form a water tank and the coal bunker to he arranged above it. A strong steel draw-bar to he riveted to the sides and back of the tender and provided with coupling pin.

PUMP

A Continuous-action Geared-down Feed Pump of ample capacity to be supplied. The Pump to be fitted with gunmetal plunger, gland, valves and seats and the requisite suction, delivery and return pipes.

This Pump runs at half the speed of the engine and its efficiency and durability are thereby much increased.

INJECTOR

An Automatic Feed Water Injector, of approved type, to he arranged as a Duplicate Feed, fitted outside and near the bottom of the tender so that the Injector does not have to lift its water.

TRANSMISSION

The Transmission Gearing to he arranged on the three-shaft or four-shaft principle. All Gear Wheels to be made of best cast steel of a specially selected quality and arranged to give two road speeds, viz. :- 1 1/2 and 3 miles per hour.

All spur gears of less than 2" pitch to have machine-cut teeth. Other gear wheels to be cast from machine-cut metal patterns, and to be of ample width and strength. All pinions to be of large diameter.

The sliding wheels for the two-speed gear to be fitted on square portions of the shaft, thus avoiding any trouble with loose keys.

The first and second intermediate shafts to be made of best quality mild steel, accurately machined, polished all over, and carefully aligned in position in brackets which are fitted with large gunmetal bearings and suitable oil cups. The brackets for the crankshaft, the intermediate shafts and hind axle to he provided with circular nipples arranged to fit into corresponding holes in the boiler horn-plates.

GUARDS

All working parts of the engine and gearing to be suitably protected with neat wrought-iron side guards; the Transmission gears outside the Horn-plates to be protected by dust proof oil-tight casings, the gears thus running in an oil-bath.

HIND AXLE

The Hind Axle to be of large diameter, made of the best axle steel, and accurately turned and polished. Four machine-cut key-ways to be provided ; two for securing the winding drum centre, and two for the bevel wheel of the differential gear.

The Keying is arranged so that the hind axle can be easily withdrawn without removing the tender.

HIND AXLE BOXES

The Hind Axle Boxes to be made of semi-steel and provided with hard gunmetal bushes of liberal dimensions. Efficient lubrication to be ensured by means of oil cups in accessible positions.

STEERING GEAR

The Steering Gear to be worked from the footplate, movement being imparted to the front rollers through a worm and wheel, quadrants, and strong wrought-lron chains. The chains to engage with a spirally-grooved barrel to ensure proper coiling.

Worm and wheel to be enclosed in dustproof casing which forms an oil bath.

BRAKE

A powerful Screw Brake capable of holding the engine on the steepest inclines, to be fitted. The brake to act direct on the hind axle, and to be placed on the left-hand of the tender within easy reach of the driver. The steel brake strap to be lined with "FERODO" fabric, a material of great strength and highly efficient braking power. "FERODO" instantly engages or releases, and possesses a durability and gripping power many times greater than hard wood; it is smooth in action and does not abrade the brake drum braking surface which therefore remains polished and true to give perfect contact.

FORE-CARRIAGE AND FORK

The Fore-Carriage to incorporate the smoke-box, chimney base, and swivel-head chamber in one casting of strong and graceful design.

The connection between the fore-carriage and boiler to be made by a machined flange, nippled to fit accurately into the flanged ring on boiler barrel and securely bolted thereto, thus ensuring a perfectly rigid joint, and reducing the working strain on the bolts.

The roller fork to be made of Cast Steel, specially selected quality, carefully machined, and so arranged as to ensure absolute freedom of movement, allow the front rollers to accommodate them-selves to uneven roads in "forward" or "backward" travel, facilitate the turning of sharp curves, and promote easy steerage.

The method adopted for connecting the fore-carriage to the boiler enables the roller to be expeditiously converted into a traction engine when required.

ROLLERS

Each Hind Roller to be made with a cast iron renewable rim; and with its hub and spokes combined in a steel casting, in accordance with our latest method which abolishes loose and broken spokes. The hub to be bushed with gunmetal. The complete rollers to be interchangeable. Spring Scrapers to he fitted ; so arranged that by the insertion of a pin they can be put out of action to allow frost pins to be used for travelling, when so required.

Each Front Roller to he made with a cast iron renewable rim; and with its hub and spokes combined in a semi-steel casting. The hub to be bushed with gunmetal. Scrapers for front and back to he provided. The front rollers to he of sufficient width to overlap the tracks of hind rollers on either side.

ACCESSORIES

Suitable lubricators to be fitted or means of lubrication to be provided for all working parts not specially mentioned.

The Outfit to consist of a Waterproof Cover (or Waterproof Curtains if a long awning is fitted), Set of Firing Tools, Flexible Tube Brush, Set of Spanners, Lamps, Oil Feeder, Tundish, Bucket, spare Gauge Classes, Frost Pins, and an Instruction Book.

GENERAL

The Engine to be constructed throughout of the best class of materials of their respective kinds, the workmanship to be of the highest description in every way, and the painting, varnishing and general finish to he of the well-known "Marshall' standard.

EXTRAS

Any of the following additional items of equipment can he fitted to this Road Roller at moderate extra charges. Clients are requested to carefully specify their requirements at the time of ordering.

GOVERNOR

A quick-speed Governor of the improved "Pickering" type, connected direct to the equilibrium throttle valve in the cylinder, and driven by a leather belt from a pulley on the crankshaft. A Speed Adjuster is fitted to the governor.

"MARSHALL FOUR-PINION" DIFFERENTIAL GEAR

Differential or Compensating Gear arranged on our four-pinion system, and provided with suitable pins which enable the gear to be quickly locked to facilitate the ascent of steep inclines and the passage over difficult ground.

The differential gear, usually considered essential for an efficient roller and strongly recommended by us, enables the engine to negotiate sharp curves, minimises strains upon the hind axle and rollers, promotes easy steering and prevents undue wear on the rollers and damage to the roads.

Our arrangement of four pinions, compared with other arrangements embodying three or two pinions, gives a better distribution of driving stresses and ensures less wear and tear.

WINDING DRUM AND GUIDEPULLEY

Cast Steel Winding Drum carrying 50 yards of flexible steel wire rope, arranged on the hind axle, and fitted with a device whereby the drum can be thrown out of gear and allowed to run loose on the axle when required. Also a Swivelling Guide Pulley of large diameter fitted in proximity to the winding drum to enable the rope to he worked over a wide radius without shifting the position of the engine.

WATER TANK

An additional Water Tank, fitted under the barrel of boiler. This item is desirable when the engine is likely to be employed as a traction engine.

WATER LIFTER

A water lifter with 26 feet of wire-armoured suction hose, and rose, fitted to the outside of the back of tender. The steam pipe inside the coal bunker to be completely encased to prevent corrosion.

FUEL RACK

A strong Fuel Rack round tender top, for use when the fuel is wood.

AWNING

Two types of Awnings are applicable, viz.:-

(a) Over the driving footplate only.
(b) Over the engine and driving footplate.
(c) As (a), but with double top with air-space, for tropical countries.
(d) As (b), but with double top with air-space, for tropical countries.

Long Awnings are fitted with waterproof side and end curtains in lieu of waterproof cover.

ROAD WHEELS & APPLIANCES FOR CONVERTING ROLLER INTO TRACTION ENGINE

Road Wheels, hind and front, suitable fore-carriage, smoke-box, steerage charm and undergear. The important feature of the convertibility of our Class "S" series of Road Rollers is that the engines are constructed so that they can be altered to traction engines at any time without special provision being made at the time of the original construction. Moreover, the fact that the engines are expressly built for the dual service does not militate in any way against their individual utility as roller or traction engine.

Marshall Sales Specification No. 310

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