Bulleid Light Pacific
West Country / Battle of Britain Class
BR Modifications and Rebuilding
For their near two-decade existence under BR auspices, alterations to the
Bulleid Pacifics were severe. Change began in 1952, when the distinct high
flanges of the tenders started to be cut down on both MN and WC/BoB engines, to
enable the pipe of a water column to be swung over freely, without obstacle.
Despite this, the tenders retained their distinct curved profile, which sat in
harmony with behind carriage stock. Two years later, boiler pressure of both MN
engines and ‘’Lightweights’’ was de-rated from 280 PSI to 250 PSI – hitherto,
the Bulleid Pacifics, matched only by the GWR’s ‘’County’’ engines, had the
highest boiler pressure rating of any steam locomotive class in the country.
Pressure reduction made the engines cheaper to maintain, permitting a more
common grade of steel to be used in the firebox. The boilers of these engines
were well designed, and from the outset Bulleid had incorporated thermic siphons
in the firebox. These were essentially steel tubes through which water was
pumped, providing locomotives with a greater overall heating surface area. The
general idea behind thermic siphons was that of conserving fuel, whilst still
raising steam production – of course, the Bulleid Pacifics were by no means
light on coal consumption!
Bulleid’s innovative features – particularly the chain-driven valve gear and oil
bath – were high maintenance items which made his Pacifics expensive engines to
operate, in addition to giving them, at times, poor availability. Consequently,
in 1954, the Chief Technical Assistant of the Locomotive Department, Brighton,
was given the task of devising a scheme which would remedy these faults. The
individual was Ronald G. Jarvis, formerly a Derby man and no stranger to the
products of Bulleid. When the latter departed for Ireland in 1949, Jarvis was
put in charge of the ‘’Leader’’ project, the scheme aimed at producing a modern
steam engine which, externally, was on a par with those double-ended diesel
locomotives later produced by BR. Five prototypes were made, but only one of
these was fully completed to working order, and the whole ‘’Leader’’ scheme was
quietly discontinued in 1951.
Jarvis’ plans outlined an extensive rebuild of every Merchant Navy and Light
Pacific, doing away with the Bulleid chain-driven valve gear, steam reverser,
and the air-smoothed casing. The steam reverser was linked to the valve gear and
regulated the timing of the valves, thus controlling the admission of steam into
the cylinders. It was capable of sending steam in above or below the pistons,
which determined whether the locomotive moved backwards or forwards. No. 34005
‘’Barnstaple’’ became the first Light Pacific to enter Eastleigh works for
rebuilding, in 1957. The rebuilding scheme had much emphasis on bringing the
appearance of Bulleid engines in line with those BR Standard Pacifics which were
then beginning to emerge. Conventional boiler cladding was fitted, which in turn
provided room for stepboards above the wheels, and BR-style smoke deflectors
were installed. The chain-driven valve gear and oil bath gave way to a more
conventional Walschaerts’ system, the inside cylinder was replaced with a new
design, and the steam reverser was abolished in favour of a screw reverser.
There was, however, discontent from across the Irish Sea, for it was later
reported that Bulleid would rather have seen his engines scrapped, than rebuilt.
On the plus side, the scheme would give his Pacifics another twenty-five years
of service life with BR, on a par with the relatively newer BR Standard classes.
At the time, it was predicted that steam traction would last up until the 1990s,
and construction of BR steam designs continued unabated.
The efforts to rebuild the Bulleid Pacifics were to be stifled. In December
1954, the British Transport Commission published a ‘’Modernisation Plan’’,
outlining the complete eradication of steam traction throughout BR in a much
smaller timeframe than originally anticipated, by means of a series of
dieselisation and electrification schemes. To set the ball rolling on SR metals
was the ‘’Kent Coast Electrification Scheme’’, approved in February 1956 and
resulting in the complete abolition of steam traction on the South Eastern
Division. Preparatory work along the ‘’Chatham’’ main line began in the
following year, concurrent with the start of the Light Pacific rebuilding
scheme. Large numbers of Bulleid’s Pacifics were allocated to the South Eastern
Divison at this time, notably at Stewarts Lane, Bricklayers Arms, Ramsgate, and
Dover. At the start of 1959, shortly before the completion of ‘’Phase I’’ of the
electrification scheme, thirty-six Light Pacifics were allocated to former
Eastern Section sheds, in addition to a trio of MN Class engines – No. 35001
‘’Channel Packet’’, No. 35015 ''Rotterdam Lloyd'', and No. 35028 ‘’Clan Line’’. The full accelerated electric
timetable commenced on the aforementioned ‘’Chatham’’ route on 15th June 1959,
but steam still remained in evidence on the ex-SER main line via Orpington, Tonbridge, and Ashford until this too witnessed a full electric schedule from
18th June 1962. Rebuilding of Bulleid Pacifics had since ceased in May of the
previous year, with No. 34101 ‘’Hartland’’ emerging from Eastleigh works as the
sixtieth – and final – modified engine. All thirty MN engines had been similarly
treated, but sadly, steam was in terminal decline.
Whilst rebuilding had brought obvious maintenance cost savings, it also yielded
some adverse side effects. Balance weights had been added to the wheels, which
gave rise to the ‘’hammer blow’’ effect on the track. Furthermore, rebuilt Light
Pacifics were over four tons heavier than their unrebuilt counterparts, which
barred them from those SR lines west of Exeter. This restriction was later
lifted, permitting them to operate between Exeter and Plymouth via Okehampton,
but clearance was never given for the route north of Coleford Junction, to
Barnstaple, Ilfracombe, and Padstow. Sadly, these lines themselves were on the
brink of severe decline, as a result of regional border changes. In September
1962, those ex-LSWR lines west of Salisbury came under Western Region control,
the latter allegedly receiving this territory, and that of the Somerset & Dorset
line, to compensate for the loss of its Wolverhampton/Birkenhead route to the
Midland Region. As a result, thirty-seven Exmouth Junction-allocated Bulleid
Light Pacifics became under the jurisdiction of the WR, and no time was wasted
in degrading the route in favour of the Paddington line via Castle Cary. Through
steam-hauled services from Waterloo to Exeter and Plymouth ceased on 4th
September 1964, and Bulleid Pacifics were replaced on these services by WR
Diesel Hydraulics – steam completely vanished from the Exeter area in the
following year.
The Waterloo to Bournemouth/Weymouth route remained as the last stronghold of
steam power on the entire SR network. Electrification of the Kent Coast lines
and dieselisation of Waterloo to Exeter (and beyond) services had ensured no
shortage of steam locomotives for this core line. With the Bournemouth
electrification programme formally receiving the green light in September 1964,
mass locomotive withdrawals began in earnest. The first Light Pacifics to
succumb were Nos. 34035, 34043, 34055, and 34074, all unrebuilt engines, which
had already been withdrawn in April 1963, as a result of the WR takeover of the
lines west of Salisbury. No. 34028 ‘’Eddystone’’ was taken out of service in May
of the following year, becoming the first rebuilt engine to be withdrawn.
Overhauls ceased, maintenance became minimal, and any spare parts required to
keep remaining locomotives serviceable were salvaged from withdrawn engines. The
last Pacific to be overhauled was rebuilt No. 34089 ‘’602 Squadron’’, which
emerged from Eastleigh Works on 3rd October 1966, less than a year before the
end of steam at Waterloo. Steam-hauled services between Waterloo and Salisbury,
and Waterloo and Southampton/Bournemouth/Weymouth, ceased on Sunday 9th July
1967. Light Pacific ‘’Dartmoor’’ was reportedly the last engine to run under its
own power between Waterloo and Nine Elms, after bringing in a boat train from
Southampton Docks.
Postscript: Cab Widths
This topic is a science in itself, with a number of variations over the engines’
existence. From the outset, front vision from cabs was reportedly poor and early
on in both MN Class and Light Pacific production, it was found that smoke had a
tendency to drift down the side of the engines, obscuring the view of the
driver. This sparked the need to install longer smoke deflectors on new builds
still emerging from Eastleigh and Brighton Works. Early production Light Pacific
examples were fitted with ‘’narrow cabs’’, which ensured engines could fit
within tight loading gauges – particularly that of the Hastings via Tunbridge
Wells Central route. However, from April 1948 onwards, starting with No. 34071,
new engines emerging from the works were fitted with wider cabs, to improve
visibility. As a result, locomotive widths increased from 8-foot 8-inches to
9-foot 3-inches.
1967
No. 34044 ''Woolacombe'' was observed at Eastleigh shed, just before withdrawal. By this time, the engine had
lost its nameplates and was wearing a makeshift smoke box number plate. On the left can be seen a ''Type 3''
diesel emerging from the shed, whilst on the right is a wasp-patterned diesel shunter, latterly ''Class 08''.
No. 34044 was withdrawn in May 1967. It had been rebuilt into its final form exactly seven years earlier.
© David Glasspool Collection
1967
This second view of No. 34044 is of interest because, on the right, it shows Eastleigh shed's lifting and repair
shop. Also on the far right can be seen the cab of a second type of diesel shunter, latterly ''Class 03'' under
TOPS. © David Glasspool Collection
1967
No. 34087 ''145 Squadron'' was also seen with a makeshift smoke box number plate and was minus nameplates,
but externally the engine looked in sound condition. The view is again at Eastleigh, and on the left can be seen
a withdrawn BR Standard 2-6-0, piston rods already removed. No. 34087 survived right until the end of steam
on the South Western Division, being withdrawn in July 1967. © David Glasspool Collection
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