Transcript Slide 1

WEST COAST TRACTION PERFORMANCE
Alstom Class 390 Pendolinos work most long-distance high-speed WCML services
Tilting trains: Fitted with TASS (Tilt Authorisation and Speed Supervision) system, which in
conjunction with track ‘balise’ transponders enables curves to be taken at
greater speeds with up to 8o of tilt on top of 6o of normal rail cant.
Fleet history : Original fleet of 53 sets
* Conceived for 8-car operation and the first 34 sets initially delivered as
such, but strengthened to 9-cars as with the remaining sets delivered
from new when it became apparent that the scaled-back infrastructure
would not be able to support the originally planned 140 mph running.
* One written off after the Grayrigg derailment in February 2007.
* Fleet now being extended by an additional 106 vehicles.
31 of the 9-car sets to be strengthened to 11-cars.
4 new 11-car sets added to the fleet.
The first of the new 11-car sets (390054) is currently undergoing
commissioning and acceptance tests on the WCML
Power at the rail of the 9-car Pendolino sets is 5.1 MW (6,836 hp)
* High power : weight ratio of 13.8 hp/tonne
* Power distributed over 12 motorised axles
* Designed for service operation at 140 mph (225 km/h)
but restricted by the infrastructure to a maximum of
125 mph in enhanced permissible speed ‘tilt’ mode.
One of the additional vehicles of the 11-car sets is motorised, only
marginally reducing the power : weight ratio to 13.3 hp/tonne
All results in Pendolinos having most impressive performance
Class 390 : Tractive Effort / Train Resistance Characteristics (9-car 67% laden)
Tractive effort and Resistance (kN)
225
200
175
150
125
100
75
50
25
0
0
10
20
30
40
50
60
70
80
90
100
110
120
Speed (mph)
Average acceleration rates on level track
0 - 60 mph 0.372 m/s2 (0.833 mph/s)
60 - 110 mph 0.218 m/s2 (0.487 mph/s)
110 -125 mph 0.127 m/s2 (0.285 mph/s)
Gradient forces
1:300 16.1kN
1:150 32.3kN
1:100 48.4kN
1:75 64.5kN
Balancing speed of 125 mph on an adverse gradient of 1:85
130
140
In normal operation then often mile after mile of sustained 125 mph running
Rarely any significant speed excesses:
- generally driven under ‘cruise’ control
- TASS over-speed alert/intervention
- drivers aware of OTMR and possibility of downloads
If tilt not working and the maximum speed is limited to 110 mph then many drivers
do their best to make up time, but workings can get out of sequence and lose pathing.
Pendolinos are eco-friendly with regenerative braking
- capable of returning full 5.1 MW back into line supply
(default to rheostatic mode if o/h line not receptive).
Blended with conventional disc friction brakes if high
braking rates are required.
Pendolinos now fitted with energy meters
- drivers informed of trip energy consumed and regenerated.
Trials with sets operating in ‘power save’ mode with 5/6 of normal traction power
- began with 4-day trial with 390049 in Nov 2008 on Mc/r workings.
Average 5% energy saving, but large day-to-day variability and was
pre-introduction of the enhanced VHF timetable.
- since March last year, power saver software installed on 10 sets to
assess effectiveness in more intensive service conditions. Typical
savings apparently 1-2%, but with reduced acceleration this comes
at the price of slightly extended journey times (more later).
Virgin had 16 Class 47 locomotives re-engined as Class 57/3 ‘Thunderbirds’
for the rescue of failed Pendolinos and ‘dragging’ of diverted workings over
non-electrified routes during engineering work. High electrical train supply
rating, and fitted with hinged Dellner couplers for ease of attachment.
Extensive dragging during the period of WCML reconstruction, but the Class 57s
are now little used other than for a weekly Saturday Only ‘knowledge retention’
working along the North Wales coast between Crewe and Holyhead (and return).
* Pendolinos have turned out to be very robust and there are few
complete failures of train sets
- unlike the WCML infrastructure which more often than is desirable
can fall apart, resulting very quickly in major disruption.
* Pendolinos and Super-Voyagers now approved to couple together
and to each other for rescue purposes.
* Frequent use of Super-Voyagers and rail replacement coaches to
avoid Pendolino drags.
Bombardier Class 221 Super-Voyager DEMUs
Used on West Coast Euston - North Wales and Birmingham - Scotland services
- until recently 18 5-car sets and 3 4-car sets, but for operational
convenience the latter have now been temporarily reformed into
2 standard 5-car sets (with the two spare driving vehicles stored).
- with relatively short trains overcrowding can be a problem, and
there is frequent criticism of using diesel power for lengthy spells
of running on electrified lines.
Again tilt-enabled with TASS control but the maximum degree of tilt of 6o is 2o less
than that of Pendolinos ,resulting in some additional lower EPS speed restrictions
- with tilt the normal running speed is 125 mph, but again restricted
to 110 mph if the tilt system is non-operational
- no cruise control facility, but with TASS and OTMR little over-speeding
Each vehicle powered by an underfloor Cummins QSK19 750hp engine with an
alternator and convertors/invertors providing 3-phase AC to 2 traction motors
- Voyager power : weight ratio at the rail is around 9.2 hp/tonne
Voyagers can (and do) operate with one or more engines out
Cross Country 5-car Class 221s accelerating after Cheadle Hulme
110
5 engines
4 engines
100
3 engines
Speed (mph)
90
80
70
On full power the normal run time of around
3.75 min for sets with all engines working is
extended by +12 secs with one engine out,
and by +33 secs with two engines out.
60
50
40
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Milepost distance (miles)
4.0
4.5
5.0
5.5
6.0
Again Voyagers normally have spare power in hand, and (without much publicity)
all West Coast and Cross Country Voyagers have now had their engines de-rated
from 750hp to 700hp
- would normally expect around a 40hp reduction in power at the rail, but
the actual reduction is apparently much less than this.
There is a proposal from Bombardier to turn Voyagers into bi-mode trains by the
addition of an un-motorised pantograph/transformer vehicle (Project Thor)
- additional passenger capacity, and a 125 mph train with a still largely
acceptable 7.9 hp/tonne.
- to many a ‘no-brainer’, but apparently little support from the DfT
(possibly because of politics associated with the Agility (Hitachi) IEP/SET
bi-mode train project).
OTHER TRACTION REGULARLY OPERATING ON THE WCML INCLUDES:
Siemens Class 350 ‘Desiro’ EMUs (LM services south of Crewe and Liverpool)
Siemens Class 185 ‘Pennine’ DMUs (TPE services north of Preston)
Class 90-powered ‘Pretendolino’ (Mk3 + DVT Pendolino stand-in)
Class 90-powered Scotrail Caledonian sleeper services
Interesting to compare the performance of the main traction types on
the southbound climb up Madeley Bank after restarting from Crewe
Typical accelerations up Madeley Bank out of Crewe
140
120
Speed (mph)
100
80
Class 390 Pendolino (full traction mode)
Class 390 Pendolino (power save mode)
Class 221 Super Voyager (all engines wkg)
Class 350 Desiro (speed limited to 100mph)
60
40
20
0
158.0
Basford Hall
Yard exit
at 156.25
157.0
156.0
Gradient
steepens
to 1:177
155.0
154.0
153.0
Gradient
eases from
1:177 - 348
152.0
151.0
Milepost distance (miles)
150.0
Madeley
summit
at 148.5
149.0
148.0
147.0
Notes for previous slide
Curves are of acceleration after clearing the 20 mph turnout from platform
P5 at Crewe to the Up Fast line.
Initial gradients are 1:330 and 269 before the 1:177 after Bentley Road.
Voyagers and Desiros have greater initial speeds as their shorter length
formations clear the turnout restriction sooner. Very similar acceleration
rates of the two types up to the Desiro 100 mph maximum permitted speed.
The power of the Pendolinos is readily apparent in their acceleration up the
bank, with standard sets reaching line speed and needing to be notched back
on the steepest gradient. In reduced power mode, the full available power is
required for longer to reach line speed just beyond the summit and modelling
suggests that any net energy saving on the climb is small (typically just a few
percent). With both the reduced power Pendolinos and the Voyagers there is
however an additional time penalty approaching ½ minute over the ~6 minute
run time of the standard Pendolinos over the same distance.
David Stannard
Railway Performance Society April 2011