SAR class 18
| SAR class 18 | |
|---|---|
.jpg) SAR class 18
|
|
| Numbering: | 1360-1361 |
| Number: | 2 |
| Manufacturer: | Henschel |
| Year of construction (s): | 1927 |
| Retirement: | 1951 |
| Type : | 1'E1 'h3 |
| Gauge : | 1067 mm ( cape track ) |
| Length over coupling: | 23,165 mm |
| Service mass: | 116.4 t |
| Service mass with tender: | 190.2 t |
| Wheel set mass : | 19.3 t |
| Driving wheel diameter: | 1,448 mm |
| Cylinder diameter: | 540 mm |
| Piston stroke: | 711 mm |
| Boiler overpressure: | 148.1 N / cm² |
| Grate area: | 5.6 m² |
| Train brake: | Suction air brake |
The vehicles of class 18 of the South African Railways (SAR) were three-cylinder steam locomotives with the wheel arrangement 1'E1 '( Santa Fe ).
The locomotives were introduced to replace the MF class mallet locomotives on the eMalahleni - Germiston route , which were not suitable for higher speeds . The existing stiff-framed locomotives were not up to the heavy coal trains that ran there.
The two locomotives delivered by Henschel in 1927 went to the limit of what was possible on the Cape Gauge. Apart from small-wheel tank locomotives, they were the first five-fold coupled locomotives in South Africa and also the first (and only) with a single-acting three-cylinder engine (triple engine). The slide movement of the inner cylinder was derived from the movements of the two outer slides (type Gresley ) via a lever system , which in turn were moved by a Heusinger control .
With a total weight without tender of 116.4 t - more than the German class 44 - the machines were significantly larger and heavier than all stiff-framed Cape gauge locomotives built up to that point, and the pulling force of 23.4 t was 75% higher than that of the Mallet and Garratt locomotives existing at the time for this gauge. In terms of total weight, the locomotives were later only surpassed by class 25 , which, however, did not achieve the tractive power of class 18.
In order to be able to drive through tighter curves with the coupled wheelbase of about six meters, the leading running axle was connected to the first coupling axle to form a Krauss-Helmholtz steering frame. In addition, the wheels of the third and fourth coupled wheel sets had no flanges, which, however, led to high flange wear on the other wheels.
Control rods also caused problems: it was too weakly dimensioned and therefore prone to repair. Overall, the locomotives could not convince, and it stayed with the two copies. They were in use until 1951 and were then scrapped.
literature
- Leith Paxton, David Bourne: Locomotives of the South African Railways. A Concise Guide. C. Strui (Pty) Ltd., Cape Town 1985, ISBN 0-86977-211-2 .
Web links
- Technical data and imaging (English)