PRACTICE&PERFORMANCE
the head of theloch and at thestartoft he longest
ascent for northboundtrains, to the Perth/Argyll
County March summit, 1,024ft abovesealevel:
aclimb broken onlyby adownhill milethrough
Crianlarich. Fullregulator and 32% cut-offsawLoch Longattaining 26mphon1-in-61, followed
by abrief33½mph onashort stretch of 1-in-103.
Steeper gradesthen brought speed down to 25½
by the ‘Fireman’sRest’, whereaclutch of gnarled
Scots pines onthelower slopes of An Caisteal
indicatestheapproach to Crianlarich, with its
refreshment facilities for locoand passengers alike.
Restarting,arapid accelerationdown to
the FillanViaductprovided impetus forthe
continuationoft he uphill battle. FortWilliam
driver Thompson was againusing 32% cut-off,
whilefireman Paterson wasmaintaining 195lb
per cent boilerpressure,Loch Longstorming away
at 31mph after two miles of 1-in-60,then falling
slowly to 23½ onthefinal 1-in-66 beforethe stopat Tyndrum (Upper). Anenergetic start saw them
over the summitat 28½mph,beforenegotiating
the HorseshoeCurvehugging the lower slopesof
Beinn Odhar,Beinn a’ Chaisteil andthemighty
cone of3,524ftBeinn Dorain. Here, the descent
is initially at1-in-55and, rather than use braking
to controlhis speed, driver Thompson adopted
the economical methodof closingthe regulator
but keeping cut-offat4 5% for ‘cushioning’ and
restraininghis mount down to Bridge of Orchy.
Surprisingly,LochLonghad lost 30 seconds
from Tyndrum.
The thirdmajor climb nowbegins to a
summitat Gortan, high up on Rannoch Moor,
and whereaformer NBR coachbody used to
serve as schoolroom forthechildrenofr emotely
based signalmen. SoLoch Longfought her way
through CrannachWood, where ashortstretch of
1-in-240/114 lifted speed momentarilyto 44mph,
after which therate hoveredabout the 30mphmark. From Gortan, theMoor wasall about
them,avastexpanse of peat, boulders and black
lochans as No.3441 ran downhill to Rannoch
station,wherethe startist he hardest ontheline.
At 1-in-53the track ascends oncheck-railed curves
over RannochViaduct through Cruach snowshed
–uniqueinBritain–toanintermediate summit by
Lochana’ Chlaidheimh,theLoch of theSword.
Here, the 2-6-0 fought up to 18mph–and
how her syncopated three-cylinder beat must have
reverberated against the snowshedroof and carried
far in those lonelysurroundings! The line then
undulates, with an uphilltendency,tot he 1,347ft
summit at Corrour,wherethe log finishes,for the
concluding 28 miles to FortWilliam arealmost
consistently downhill.
As they were specifically intendedforthe
West Highland, onlysix ‘K4s’ werebuilt,given
such evocativenames asCameronofLochieland
Lordofthe Isles.However,when summer loadings
exceeded their 300-ton limit, ‘K2’or‘ Glen’
pairingshad to be used as the high axleload of the
new Moguls meant they could not be piloted.
With the drop in maintenance standards
during theSecondWorld War, the ‘K4s’, with
their 5ft2in coupledwheels, were givingtheir
crewsrough rides on the comparatively fast stretch
between Glasgow and Craigendoran.InBRdays,
therefore, they were concentrated on the Mallaig
Extension and confined to freightduties on the
West Highland proper until1959 sawthem
transferred from Eastfield (Glasgow) to Thornton
Junction, chieflyfor freight work in Fife: not what
Sir Nigel had intended!Achilles heel
Anothertype ofloco triedonthe West
Highland,but with less success than the ‘K4’,
was Gresley’s finalsteam design, the ‘V4’ 2-6-2.
Justifiably pleased with his ‘V2’2-6-2s,he
consideredaminiatureversion with wideroute
availability would be ideal. Nos. 3401Bantam
Cockand 3402(unofficially,Bantam Hen)
wererolled out from Doncaster in 1941 and
proved themselvesin East Anglia andelsewhere.
Gresley’s continued use, onamixed-traffic loco,
of conjugatedvalve gearand th reecylinders
neverthelessproved unwise. And,inc ontrast
to his early Pacifics, with their 180lbperinch
boiler pressure, he hadnow gone totheopposite
extreme and given the‘Bantams’ 250lbboilers.
From 1943 to 1949 the‘V4s’ werebased
at Eastfield andoften ventured on to theWest
Highland, wherethey rode the curves well and,
with their wide grates, wererelatively easy to fire.
TheirAchilles heel was the theoreticalhigh boiler
pressure, whichcould not always be maintained.In
his description of an UprunonNo. 3401,
OSNock wrote: “Starting (from FortWilliam)
with 235lbonthe ‘clock’,weweredown to 180
beforeSpean Bridge...however, we managedto
struggleinto Corrour,having fallento 15½mph
on thewayup. Thelowestpressurerecorded was
170lb”... This, he pointed out,reduced nominal
tractive effortto1 8,600lb, less than that of a
‘Glen’.
Following Gresley’sdemise in 1941,his
successor as chief mechanicalengineer,Edward
Thompson,cancelled the order formore ‘V4s’ and
developed instead themore versatile two-cylinder
‘B1’ 4-6-0. As thoroughbreds ratherthan rough-
and-tumble workhorses, the ‘V4s’had notbeen
‘right’ for theWest Highland.
Thompson also converted many of Gresley’s
otherthree-cylinder locostoc onventional
two-cylinder machines. Thus‘K4’ No.3445
MacCailin Mor(later ,BRNo. 61997) became the24 •TheRailway Magazine•August2019
Train: 5.46am Glasgow(Queen Street)-Mallaig 10.05amQueen Street-Mallaig
Locos: ‘LM5’4-6-0s Nos 44908/45396 ‘LM5’4-6-0s Nos 44956/44973
Load: 9incl 2vans,289½/305tons 8/274½/295tons
Recorder: JNGProudlock GAMWood
Date: October4,1 954 August 21, 1961Miles Timing Point Sched Actual Speed Sched Actual Speed Gradient
min ms mph min ms mph 1-in
0.0 DUMBARTON(C)0000-/460000- 385R
3.8 Cardro ss 615- pass -03F/175R
3.8 Cardro ss spl stop 700-/45 43 52/54 236F
7.3 Craigendoran Jct 13 15 25* 10 08 10* Level
7.5 Craigendoran Upper pass 11 10 42 -60R
7.5 Craigendoran Upper 12/0 11 29/0 -58R
8.3 MP 1 /r 30max 2392 2/24½ 58R
9.5 Helensburgh Upper 16 18 40 6½ 534- 58R
0.0 Helensburgh Upper 17/0 19 30/0 -/28 7/0 630/0 -/28 L/67R
1.8 Rhu 4302 4*/42 4003 5/48 88R/100F
4.5 Shandon 8452 0*/35 7532 2*/40 L/68F
6.9 Garelochhead pass 15 12 18 -92F/60R
6.9 Garelochhead 14 13 25 20*/27 16/0 13 18/0 -/25 61R
8.2 Whistlefield 17 00 24*/35 4272 1/37 58R/122R
13.2 Glen Douglas 29 27 50 22*/38 15 14 55 10*/42 89R/56F
17.5 Arrochar&Tarbe t3 83 530- 25 22 45 -53F/69R
0.0 Arrochar&Tarbe t39/0 39 00/0 -/40 26/0 26 12/0 -/47/* tsr 225R/105F
8.0 Ardlui 15 13 47 -1 61 318- 130R/66F
0.0 Ardlui 20/0 18 05/0 -2/0 23 29/0 -/32 68R/61R
2.3 MP 30 n/r 25/29 6192 7/33½ 61R/73R
6.3 “34n/r 14 07 27/35/0* +60R/423R
8.7 CRIANLARICH (U) 20 19 43 -2 22 025- 60R/66F
0.0 CRIANLARICH (U) 28/0 27 55/0 -/34 29/0 28 09/0 -/36 64F
3.6 MP 40 n/r 27 7433 2/27 60R/66R
5.0 Tyndrum Upper 12 11 50 -pass 66R
0.0 Tyndrum Upper 13/0 12 15/0 - 0401 9*/31 60R
1.4 MP 43 n/r 26/50 14 26 30/*/50 60R/55F
7.5 Bridge of Orchy1 41 315- 26 23 40 -77F
0.0 Bridge of Orchy15/0 14 35/0 -/30 27/0 26 52/0 -/27 74 R/200F
2.9 MP 52 n/r 48/31 5574 5/29 240R/60R
5.9 “55n/r 11 36 30/36 66R/81R
8.6 Gortan 18 17 10 -ass 84R/66R
8.6 Gortan 19 19 30 -/40/20* 17 16 19 21*/50 60F/148F
15.6 Rannoch 30 30 28 -tsr 29 27 01 -50R
0.0 Rannoch 31/0 32 10/0 -0/0 28 59/0 -53R
1.3 MP 66 n/r 22 4162 5½ 53R
4.3 “69n/r 39 9104 8/19*tsr 86R/83F
7.3 Corrour 15 15 10 -15½ 15 08 -140R
0.0 Corrour 16/0 16 15/0 -/44 16/0 16 07/0 -/36 59F
10.0 Tulloc h2 01 745- pass 67F/59F
0.0 Tulloc h1/0 18 25/0 -/38 19 00 10*/40 59F/126F
5.8 RoyBridge 10 10 20 -30½ 29 17 -64F
0.0 RoyBridge 11/0 11 10/0 -/38 31/0 30 48/0 -/42/5* 84F
3.3 Spean Bridge 5700 -5659-sigs 188F
0.0 Spean Bridge 10/0 13 10/0 -/42 24/02409/0 -/47 100R/80F
8.2 Mallaig Junction pass arr 14 06 0* sig 59F/716F
13 12 20 27* dep 20 20 -stopLevel
Locodepot pass arr 22 48 0* LD Level- ep 24 18 -Level
9.2 FORT WILLIAM1 61 500- 17 26 55 -Level
n/r =not recorded +=sig. stop 14sec LD =No. 44 956 detached
TABLE 2:DUMBARTON-FORTWILLIAM