SAR Beyer Garrett 4 - 8 - 2 + 2 - 8 - 4 Locomotives

Locomotives of the South African Railways (S.A.R.)
Beyer Garrett 4 - 8 - 2 + 2 - 8 - 4 Locomotives.
Gauge 3 ft. 6 inch.
Leading dimensions are as follows:
Cylinders (4), diameter by stroke:
18½ in. by 26 in.
Coupled wheels, diameter:
4 ft.
Bogie wheel, diameter:
2 ft. 4½in.
Truck wheel, diameter:
2 ft. 10 in.
Wheelbase, rigid :
13 ft. 4½ in.
Maximum axle load:
15 tons
Adhesive weight:
115 tons
Total weight, in working order:
184½ tons
Boiler pressure:
200 lb. per sq. In.
Heating surface:
Tubes:
36 flue, 5½ in. outside diameter:
282 small, 2 in. outside diameter:
2,328 sq. Ft.
Firebox, including arch tubes:
Total evaporative:
Superheater, 1½ in. diameter tubes:
Total:
212 sq. ft._
2,540 sq. ft.
463 sq. ft._
3,003 sq. Ft.
Grate area:
51.3 sq. Ft.
Coal capacity:
10 tons
Water capacity :
5,650 gallons
Tractive effort: At 85 per cent. B.P:
At 75 per cent. B.P:
63,030 lb.
55,620 lb.
Locomotives of the South African Railways (S.A.R.) Beyer Garrett 4 - 8 - 2 + 2 - 8 - 4 Locomotives. Gauge 3 ft. 6 inch.
The majority of the 200 "Garratt" type locomotives in service on the S.A.R. have been used on the numerous branch lines
throughout this great railway system. Most of these are single and are laid with 60 lb. rail. The traffic on many of them has
attained main line proportions and a great deal of money has been spent on re-alignment to reduce curves and grades, but,
nevertheless, long sections of 1 in 50, 1 in 40 and even 1 in 30 with sharp curvatures still abound.
The latest design of engine power for the South African Railways is a general purpose locomotive to meet these conditions,
and by the courtesy of Beyer, Peacock & Co., Ltd., we illustrate these remarkable machines, of which no less than fifty were
ordered during the war, and a number of which have now been shipped. This order is one of the largest for locomotives
ever placed in this country by an overseas railway, and the largest order for articulated engines ever placed in the world.
The Class G.E.A. locomotive is one of the most powerful built for 60-lb. rail operation with a tractive effort of over 60,000 lb.
The first eight-coupled "Beyer-Garratts" were supplied by Beyer-Peacock to the South African Railways in 1925, and had a
2-8-2+2-8-2 wheel arrangement (Class GE).
The new design, although developed from the old Class GE, bears little resemblance to it except for the boiler, which is
interchangeable, being of a completely new design embodying the latest practice of the railway and the makers. Certain
alterations and improvements have been made, i.e., the firebox, round top instead of Belpaire, is of steel instead of copper,
pressure 200 lb. instead of 180 lb., and increased superheating surface. The wheel arrangement has been extended to 4-82 + 2-8-4 to permit increased coal and water supplies, and the coupled wheel has been increased from 3 ft. 9½ in. (later
altered to 3 ft. 10 in. in South Africa) to 4 ft. 0 in. The engine unit chassis now have bar frames instead of plate. The axle
loading is of unusual interest:
a maximum of nearly 15 tons is reached on the driving wheel, instead of a normal 13 or 13½ tons. The weights, however,
decrease towards the extremities of the units. Thus a tractive effort at 85 per cent, boiler pressure of 63,030 lb. is obtained,
with a total weight of locomotive in working order of 184½ tons. The engine is designed to negotiate a minimum curve of
275 ft. radius with 4½ in. super-elevation and gauge widening not exceeding 3/16 in. It will be noted that all coupled wheels
have full flanges according to the latest practice of the railway, the rigid wheelbase being 13 ft. 4½ in.
Weight distribution and balancing has received particular attention, and the revolving weights are completely balanced in
each wheel. Three-point suspension with overhung spring gear is arranged — the inner bogie and coupled wheels
providing two points and the outer four-wheeled bogie the third.
Cast-iron is used for the cylinders, which are integral with the box-section exhaust passages and bolted together in the
middle. Right and left-hand castings are interchangeable, and have renewable liners in both cylinder barrel and steam
chest. The cylinder and steam chest covers, embodying the valve-spindle guides, are of cast-steel. Pistons are of box type,
having three narrow rings; Hendrie -type by-pass valves and an air valve of the standard S.A.R. design are mounted on
each cylinder. The piston rods are made from steel of 32-38 ton tensile with the piston head secured by cone and nut.
Asbestos mattress is used for lagging the cylinders, with an outer clothing of mild steel and with stainless steel casings for
the cylinder and steam chest covers, giving a very smart appearance. The crossheads are of Laird type, in cast steel, with
cast-iron slippers and full white-metal facings. Soft grease is introduced through the gudgeon pin to the small end.
In accordance with recent practice on certain Beyer-Garratt engines, the die block of the Walschaerts gear is placed in the
direct half of the link on both engines for forward gear. A maximum of 75 per cent, cut-off is obtained in full gear with a valve
travel of 6½ in. The eccentric rods have Hoffman ball bearings at the eccentric crank end, and roller bearings at the
reversing link. Ajax soft-grease lubrication is used for the whole of the valve gear. The connecting rods, of Tormanc hightensile alloy steel, have bronze floating bushes working in a fixed steel bush in the big ends and solid bronze bushes in the
small ends. The coupling rods are of steel of 32-38 ton tensile strength with bronze floating bushes running in fixed steel
bushes. All rods are lubricated by Ajax bayonet-type hard grease nipples with soft grease for the knuckle-joint pins. The
standard-type S.A.R. steam reversing gear is employed.
The joints of the steam and exhaust pipes have cast-iron half-lens rings, and, in accordance with Beyer-Peacock practice,
the steam ball joints have a cast-iron ball in a cast-steel socket. Exhaust ball-joints comprise gunmetal balls and cast-steel
sockets, with cast-iron slip joints.
These locomotives are well up to the loading gauge, and boiler mountings are consequently specially designed. The two
steam turrets follow the shape of the firebox shell and are placed outside the cab. They have main shut-off valves and
incorporate the main steam valves for all auxiliaries. There are two 3½ in. Ross pop safety valves and two Davies and
Metcalfe No.13 live-steam injectors with 11.5 mm. Monitor cones, supplied with steam through Sellars valves. Delivery is
through a Duplex top-feed clackbox in front of the dome, and in front of this is mounted a steam release valve.
The bar-type main frames are of rolled open-hearth basic steel, 4 in. thick and of 32-38 tons tensile strength, braced
throughout with stout frame stretchers of cast steel. The pivots, which are of the latest Beyer-Peacock patent inverted
adjustable type, are integrally cast with heavy cast-steel cross stretchers. It is considered that this construction will last the
full life of the engine. The pivot centre bearings have oil lubrication and grease lubrication is provided for the adjustable
blocks. Side roller bearings of the latest Beyer-Peacock type are provided. The locomotives have been designed and built
by Beyer, Peacock & Co., Ltd., Manchester, to the special requirements of Mr M. M. Loubser, the Chief Mechanical
Engineer, while the construction and testing of the first engines have been carried out in collaboration with and under the
inspection of Mr W. H. Maass, Acting Advisory Engineer, South Africa House, London. Latterly the locomotives have come
under Mr L Douglas, the present Advisory Engineer,
The first locomotives shipped to Port Elizabeth for erection at Uitenhage, from where they will be distributed. Destinations
include the North Coast Line which runs 250 miles northwards from Durban and the Mossel Bay – Oudtshoorn line which
contains the famous 1 in 36 and 1 in 40 sections crossing the Outeniqua Mountains. A number will also operate in the
Pretoria district. It is at any rate evident that the sphere of operation of the Beyer Garrett type locomotive will be
considerately extended throughout the union by their arrival.
Locomotives of the South African Railways (S.A.R.) Beyer Garrett 4 - 8 - 2 + 2 - 8 - 4 Locomotives. Gauge 3 ft. 6 inch.
All controls are placed in accessable positions. In the teak - lined double roof are roller slide ventilators, and there are also
ventilating doors in the cab front and sides. In the centre of the back plate sliding fire door is mounted a Clyde soot blower.
Gauges, sight - feed lubricators, and reversing sector are illuminated electrically, and there are also lights mounted outside
the cab back for the coal bunker and forward of the firebox to enable the crew to see the injector overflow.