Southwick Tramway 0-4-0 Locomotives in Great_Britain

Class Grieg and Aveling (Locobase 20860)

Data from "Greig and Aveling's Tramway Engines", Engineer, Volume 64 Engineering, Volume 64 (21 October 1887), p. 328.

Designed for short runs on street railways, this tram engine had many of the qualities of the type, but offered several variations on the theme. One of the most noticeable was the placement of the drive train, including the crank axle, above the locomotive-style boiler. Two pistons drove the cranks, which turned the axle. On the left side of the locomotive, a 9" (227 mm) pinion gear meshed with the 40" (1,016 mm) intermediate wheel, which was mounted over the gap between the two street-level axles. The teeth of the intermediate wheel meshed with the 27" gears that lay inboard of each of the drivers.

"Thus all of the wheels are driven without the necessity of coupling rods, and this, especially on such flinty dusty roads as those at Southwick,effects, it is claimed, a great saving of wear and tear." (Locobase wonders whether drivng both axles at once could sustain even engagement of the axle gears by the intermediate wheel.)

To avoid the use of conventional springs, the tram motor used "spring tires". These contained internal springs, but Engineer's report couldn't quite spell out how they worked. Assuming they were effective, the tires eliminated the need for horn bars and sliding axle boxes as "each wheel can give independently of the other and follow the inequalities of the road."

The roof mounted condenser held 208 sq ft (19.23 sq m) of 1" tubes laid across the body. A tank took the steam first to reduce water entering the condenser. Blackman's horizontal fan pulled air from the two condenser halves and sent it up the stack to induce a draught, "which is of some advantage".

The engine was "most easily and perfectly under the control of a lad who stands in the centre and has everything under his eyes and within hand reach."

Engineer wrapped its favorable report by noting several advantages. All of the moving parts had been placed "completely away from dust and dirt", the engine worked "with an entire absence of smoke and steam, almost without noise" in service where the high piston speed aided response to stopping and starting, "a very desirable thing on lines where this occurs so frequently as on street tramways."