The Great Northern Railway (Ireland) SG and SG2 classes was one of the last designs of Charles Clifford. They were primarily intended for goods work, but the increased wheel diameter enabled effective passenger duties, managing heavy excursion trains with ease and speed. Beyer, Peacock & Company built the first two batches in 1913 and 1915 and the 1924-25 batch were built by Nasmyth, Wilson & Company.

Design

They were the first GNR designs to be fitted with

Schmidt Schmidt may refer to: * Schmidt (surname), including list of people with the surname * Schmidt (singer) (born 1990), German pop and jazz singer * Schmidt (lunar crater), a small lunar impact crater * Schmidt (Martian crater), a List of craters on ...

superheaters and piston valves, the SG class having a re-designed motion with rocker arms as well as the first to have wheels instead of . Engines were originally built with flush riveted

smokebox A smokebox is one of the major basic parts of a steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is e ...

es. After the first major overhaul, domed rivets were used. These locomotives originally ran with flared tenders, but at a later date straight sided tenders were also used. When first brought into service, the five SGs were originally numbered 137, 138, 37, 40 and 41. The last three were renumbered 47, 48, 49 and the whole series was finally renumbered 175, 176, 177, 178, 179.

Differences

The major difference was in the brake rods of which there were two inboard of the wheels. The earlier SO and 562 locomotives had four pull-rods, the outer ones being outside of the wheels. The 1915 batch (Classified 52 and 502) had direct motion, without rocker arms, driving inclined piston valves, and

Robinson Robinson may refer to: People and names * Robinson (name) Fictional characters * Robinson Crusoe, the main character, and title of a novel by Daniel Defoe, published in 1719 Geography * Robinson projection, a map projection used since the 1960 ...

superheater. The only external difference was that the shaft and reversing rod were a little higher which resulted in the rear of the left hand side sandbox rod being inclined upwards from the centre sandbox back to the

firebox Firebox may refer to: *Firebox (steam engine), the area where the fuel is burned in a steam engine *Firebox (architecture), the part of a fireplace where fuel is combusted *Firebox Records Firebox Records was a Finnish record label based in S ...

. The Wakefield

mechanical lubricator An automatic lubricator is a device fitted to a steam engine to supply lubricating oil to the cylinders and, sometimes, the bearings and axle box mountings as well. There are various types of automatic lubricator, which include various designs ...

was mounted further back on the 502. These locomotives were also fitted with Ross pop

safety valve A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds ...

s as built. The 1913 batch had lever safety valves changed to Ross pop type after first major overhaul after 10 years.

CIÉ ownership

On the break-up of the GNR in 1958, Córas Iompair Éireann took over a number of these locomotives for a period of five years up to the end of steam on CIÉ. They were used particularly on the ex-

Dublin and South Eastern Railway The Dublin and South Eastern Railway (DSER), often referred to as the Slow and Easy, was an Irish gauge () railway in Ireland from 1846 to 1925. It carried 4,626,226 passengers in 1911. It was the fourth largest railway operation in Ireland oper ...

services to Wexford and Rosslare. CIÉ retained the GNR numbers, with suffix N except in the case of No.19, also ‘CIE’ was stencilled on the locomotive

buffer beam A headstock of a rail vehicle is a transverse structural member located at the extreme end of the vehicle's underframe. The headstock supports the coupling at that end of the vehicle, and may also support buffers, in which case it may also be ...

s. After withdrawal, some locomotives, including 15N, 179N, and 181N were kept in reserve by CIÉ, some until 1965.

Model

The SG Class is currently available as a 00 gauge etched-brass kit fro
Studio Scale Models
It includes transfers, brass etches, most nameplates and cast white metal parts.

Design

Differences

CIÉ ownership

Model

References

Further reading