IRSE Sept 08.indd

TAFF VALE
IRSE
As a consequence of the passenger services expanding on the
Aberdare line, Abercomboi Signal Box closed and Abercynon took
over control by an NX panel with SSI control in 1988 replacing the
token system. With Abercomboi closing Abercynon gained the
Train Staff working to Tower Colliery via the Shunters based at
Aberdare yard. The only remains of the Ynysbwl branch are the
connections at Stormstown yard as the single line was lifted after
the Windsor colliery closed in 1988. Black Lion Signal Box closed
in 1992 after being condemned by the Health & Safety Executive
as structurally unsafe which forced the closure of the passing loop
at Merthyr Vale. This in turn reduced the Merthyr service from
1/2 hourly to hourly, the token system being converted to “No
Signalman Token Working” from Abercynon to Merthyr.
The connections at Abercomboi were rationalised with the
closure of the furnacite plant in 1996 leaving only the passing
loop. The Train Staff at Aberdare with the withdrawal of the
shunters, was incorporated into the Annett’s release instrument at
Aberdare Ground Frame by the Signal Maintenance Engineer
(original staff stolen from unmanned Aberdare shunters cabin).
Abercynon Signal Box this century
In the last few years, passenger services have increased requiring
greater capacity. The Aberdare line, Mountain Ash diversion,
required the original GEC panel to be replaced by a Tew panel to
incorporate the additional passing loop at Mountain Ash in 2004 .
The Aberdare line’s only Axle Counter AzL 70/30 was also
replaced by AzL(M) at the Abercynon end of the line leaving a
mixture of TI21’s and d.c. a.c.-Immune track circuits (the other
AzL 70/30 was removed as part of the Mountain Ash scheme).
The Signals are a mixture of Dorman LED and conventional
Colour lights. The SSI being re-controlled from the new Signal
box. Both loops on the line have HW2000 style point machines.
At the Aberdare end of the SSI controlled area is Aberdare
Ground Frame with spring catch points which allows trains off the
passenger line onto the freight only line without using the Ground
Frame. The travelling Shunter can obtain the staff by getting a
release of the Ground Frame and withdrawing the
Annett’s key which releases the Staff. The Annett’s key
is then replaced and the train proceeds up to Tower
Colliery.
The scheme to allow half-hourly services to Merthyr funded by
the Welsh assembly has been achieved by re-signalling and remodelling
the junction. Abercynon crossovers at the south were
removed and replaced at the North of the South Station (South
only catered originally for Merthyr trains). The new Abercynon
Station having island platforms via the new scissor crossovers it
allowed the closure of the North station. (Abercynon North station
was built for the original 1988 Aberdare scheme), also the
provision of a two mile passing loop at Merthyr Vale Up line
directional and the down line bi- directional.
The new Abercynon Signal Box is a double storey portacabin
building, upstairs the new Signal Box and downstairs the
Interlocking. The new signalling is controlled by VDU’s with
interface by WestCad with two SSIs & Train Describer, the track
circuits are being provided by AzL(M) Axle Counters with two
Evaluators, new Signals are all Dorman LED type. Point machines
on the scheme used HW2000 point motors. The single line
beyond the passing loop will be worked as “One Train working
controlled by Axle Counters up to Merthyr.
The line has two level Crossings the first is at Robertstown
which is a TMO style crossing with two Western region barriers,
the next is Hirwaun which has two gates only.
The Stormstown Interlocking control system has been moved
from the old Signal Box and reused in the new Signal Box. The
new Westcad has all of Stormstown area although it is track
layout only until later in the year when the SSI will be expanded to
incorporate Stormstown controls and indications. Stormstown
has a mixture of track circuits of low voltage d.c. and Aster types,
signals are conventional colour lights with LED shunt signals, and
the point mechanisms are Clamp Locks.
IRSE
NEWS Issue 137 September 2008 17