Cab forward

With Cab Forward Locomotive (English about cab front) are called steam locomotives that run contrary to the usual construction with the cab forward.

The main advantage of this design is considered significantly better forward visibility because the field of vision of the locomotive engineer is not restricted by the boiler. The major disadvantage, which has prevented the further spread of this design are the problems with the fuel supply.

If you switch the boiler in its usual position, ie with the firebox at the rear end, as engineer and fireman are spatially separated from each other and therefore can not support each other and communicate only via a mouthpiece with each other. Locomotives of this design were, for example, the 2'B3' locomotive by the French engineer M. Thuile with 2,50 m large driving wheels and the Prussian experimental locomotives S 9 ( 2'B2 ', see picture) and T 16 ( 2'C2 ' t).

The placement of the boiler with the firebox front, so the cab, solves this problem, but will cause a running behind the locomotive tender with lump of coal is no longer possible. Because a pushed Tender for reasons of operational reliability is undesirable and also, in turn, leads to an obstruction of view, the carbon stock must be placed either on the locomotive itself, which is useful due to the limited loading gauge only up to a certain size of the boiler, or furnace has a fuel take place, which can be conveyed to the cab in pipelines from the Tender. For this, coal dust and oil are.

The most successful cab-forward locomotives with coal boxes on the locomotive itself were the vehicles of the genus Gr670 and Gr671 the South Adriatic railway in Italy. They had the wheel arrangement 2'C, and the ongoing behind the locomotive Tender contained only the water supply. The machines were from 1900 to the 1940s in use. The Gr672 was a further development of this type with a Franco -Crosti feed water in the tender.

In the German 05 003 the solution of a pulverized coal has been selected. But on the long road between tender and firebox is segregated, the aided by a blower flow of air and coal dust so that the dust just burned incompletely. The problems eventually led to the locomotive " turned around" and was converted into the conventional -fired piece of coal type, which was provided in the event of the failure of attempts from the beginning.

The successful addition to the Italian machine cab-forward locomotives that have this designation also marked, were the 244 locomotives of the classes AC - 1 to AC -8 and AC - 10 to AC-12 Southern Pacific Railroad. The articulated locomotives with the wheel arrangement 2'd (D1 ') were fired with oil and thus avoided the 05 003 in the problems encountered. Motivation for the introduction of this type were not the better visibility, but the problem is that the crews of conventional locomotives were exposed in some long tunnels and avalanche galleries so much the smoke of their own locomotive that had to be driven with gas masks. Some train drivers went on to turn their engines and drive back through the tunnel, from which the idea for the " Cabforwards " was born.