GNRI Class SG
Encyclopedia
The Great Northern Railway (Ireland) SG and SG2 classes was one of the last designs of Charles Clifford. These locomotives were the first GNR(I) designs to be fitted with Schmidt
superheater
s and 8 inches (203 mm) piston valves, the SG class having a re-designed motion with rocker arms as well as the first to have 5 in 1 in (1.55 m) wheels instead of 4 in 7 in (1.4 m).
More locomotives were added in 1915, but with further alterations from Clifford’s design. Classified 52 and 502, They had direct motion (without rocker arms) driving inclined piston valves, and Robinson superheater. The only external difference in respect of the model was the weighshaft being a little higher on the S02 resulting in the reversing rod being higher, which in turn resulted in the rear of the left hand side sandbox rod being inclined upwards from the centre sandbox back to the firebox. Also the Wakefield mechanical lubricator was mounted further back on the 502. These locomotives were also fitted with Ross pop safety valve
s as built. The 1913 batch had lever safety valves changed to Ross pop type after first major overhaul after 10 years.
Engines were originally built with flush riveted smokebox
es. After first major overhaul domed rivets were used. A further batch of 502’s were built in 1924/25 by Nasmyth, Wilson and Company, the previous two lots having been built by Beyer, Peacock and Company
. The major difference was in the brake rods of which there were two inboard of the wheels. The earlier SO and 562 locomotives had 4 pull-rods the outer ones being outside of the wheels. (Photos suggest that some of these locomotives were converted later to inner pull-rod type.) The other differences for the modeller to note are that the 1924 batch had beading on the splasher sides above the sub-splashers, and of course were fitted with triangular Nasmyth, Wilson builders’ plates on the leading splashers. Beyer, Peacock locomotives of 1913 and 1915 had oval plates on the centre splashers.
Although primarily intended for goods work, the increased wheel diameter was intended to allow use for passenger duties, and they proved most useful for some passenger work and took heavy excursion trains with ease and speed.
When first brought into service, the five SG’s were originally numbered 137, 138, 37, 40 and 41. Very soon, however, the last three were renumbered 47, 48, 49 and the whole series again renumbered 175, 176, 177, 178, 179. These locomotives originally ran with flared tenders, but at a later date 3500 gallons (15,911.3 l) straight sided tenders, as supplied in the kit, were also used. All locomotives were fitted with 3 link couplings and tenders with screw couplings.
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-DSER
services to Wexford and Rosslare
. CIÉ retained the GNR(I) numbers, with suffix N except in the case of No.19, also ‘CIE’ was stencilled on the locomotive buffer beams. After withdrawal, some locomotives, including 15N, 179N, and 181N were kept in reserve by CIE, some until 1965.
Wilhelm Schmidt (engineer)
Wilhelm Schmidt, known as Hot Steam Schmidt was a German engineer and inventor who achieved the breakthrough in the development of superheated steam technology for steam engines....
superheater
Superheater
A superheater is a device used to convert saturated steam or wet steam into dry steam used for power generation or processes. There are three types of superheaters namely: radiant, convection, and separately fired...
s and 8 inches (203 mm) piston valves, the SG class having a re-designed motion with rocker arms as well as the first to have 5 in 1 in (1.55 m) wheels instead of 4 in 7 in (1.4 m).
More locomotives were added in 1915, but with further alterations from Clifford’s design. Classified 52 and 502, They had direct motion (without rocker arms) driving inclined piston valves, and Robinson superheater. The only external difference in respect of the model was the weighshaft being a little higher on the S02 resulting in the reversing rod being higher, which in turn resulted in the rear of the left hand side sandbox rod being inclined upwards from the centre sandbox back to the firebox. Also the Wakefield mechanical lubricator was mounted further back on the 502. These locomotives were also fitted with Ross pop safety valve
Safety valve
A safety valve is a valve mechanism for the automatic release of a substance from a boiler, pressure vessel, or other system when the pressure or temperature exceeds preset limits....
s as built. The 1913 batch had lever safety valves changed to Ross pop type after first major overhaul after 10 years.
Engines were originally built with flush riveted smokebox
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 exhausted to the atmosphere through the chimney .To assist...
es. After first major overhaul domed rivets were used. A further batch of 502’s were built in 1924/25 by Nasmyth, Wilson and Company, the previous two lots having been built by Beyer, Peacock and Company
Beyer, Peacock and Company
Beyer, Peacock and Company was an English railway Locomotive manufacturer with a factory in Gorton, Manchester. Founded by Charles Beyer and Richard Peacock, it traded from 1854 until 1966...
. The major difference was in the brake rods of which there were two inboard of the wheels. The earlier SO and 562 locomotives had 4 pull-rods the outer ones being outside of the wheels. (Photos suggest that some of these locomotives were converted later to inner pull-rod type.) The other differences for the modeller to note are that the 1924 batch had beading on the splasher sides above the sub-splashers, and of course were fitted with triangular Nasmyth, Wilson builders’ plates on the leading splashers. Beyer, Peacock locomotives of 1913 and 1915 had oval plates on the centre splashers.
Although primarily intended for goods work, the increased wheel diameter was intended to allow use for passenger duties, and they proved most useful for some passenger work and took heavy excursion trains with ease and speed.
When first brought into service, the five SG’s were originally numbered 137, 138, 37, 40 and 41. Very soon, however, the last three were renumbered 47, 48, 49 and the whole series again renumbered 175, 176, 177, 178, 179. These locomotives originally ran with flared tenders, but at a later date 3500 gallons (15,911.3 l) straight sided tenders, as supplied in the kit, were also used. All locomotives were fitted with 3 link couplings and tenders with screw couplings.
CIÉ ownership
On the break-up of the GNR(I) in 1958, Córas Iompair ÉireannCóras Iompair Éireann
Córas Iompair Éireann , or CIÉ, is a statutory corporation of the Irish state, answerable to the Irish Government and responsible for most public transport in the Republic of Ireland and, jointly with its Northern Ireland counterpart, the Northern Ireland Transport Holding Company, between the...
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-DSER
Dublin and South Eastern Railway
The Dublin and South Eastern Railway was an Irish gauge railway in Ireland from 1846 to 1925.It was incorporated by Act of Parliament in 1846 as the "Waterford, Wexford, Wicklow and Dublin Railway Company". In 1860 it was renamed the "Dublin, Wicklow and Wexford Railway Company" and on 31...
services to Wexford and Rosslare
Dublin-Rosslare railway line
The Dublin-Rosslare railway line is a main rail route between Dublin Connolly station and Rosslare Europort, where it theoretically connects with ferry services to the United Kingdom and mainland Europe. The line between Dublin and Greystones is electrified and forms the southern part of the DART...
. CIÉ retained the GNR(I) numbers, with suffix N except in the case of No.19, also ‘CIE’ was stencilled on the locomotive buffer beams. After withdrawal, some locomotives, including 15N, 179N, and 181N were kept in reserve by CIE, some until 1965.
See also
- Diesel Locomotives of IrelandDiesel locomotives of IrelandAlthough prototype diesel locomotives ran in Britain before World War II, the railways of both the Republic and Northern Ireland changed over much more rapidly from steam to diesel traction, in the 1950s than those in Britain, due to the island's limited coal reserves and ageing steam locomotive...
- Multiple Units of IrelandMultiple Units of IrelandA wide variety of diesel and electric multiple units have been used on Ireland's railways. This page lists all those that have been used. Except with the NIR 3000 class the numbers given by each class in the lists below are those allocated to the coaches that make up the units in that class,...
- Coaching Stock of IrelandCoaching Stock of IrelandA wide variety of hauled coaches have been used on the railways of Ireland. This page lists all those since 1945.-Republic of Ireland:When formed in 1945, Córas Iompair Éireann inherited from its constituents a motley collection of coaching stock from various manufacturers, in equally variegated...
- Steam locomotives of IrelandSteam locomotives of IrelandA wide variety of steam locomotives have been used on Ireland's railways. This page lists all those that have been used in the Republic of Ireland and Northern Ireland...