UK RAILWAYS

After a recent bridge strike by a lorry in Edinburgh (where St. Margarets
steam shed used to be) I noticed that all the different operating companies
used a different speed over the bridge. The EWS driver on the binliner to
Dunbar stopped, got out and had a look at the bridge whereas Scotrail trains
crawled over it, GNER used walking pace and Virgin about 20-30mph. Who sets
the speed limit and how is that limit communicated to the various companies
and their drivers?

--
Neil McD.

Apologies in advance for the long- windedness nature of this response and
for top- posting.

The following arrangements applied prior to maintenance transferring back to
Network Rail. (I assume that current arrangements are little different.)

Subsequent to a bridge strike, the line is inspected by two people. One is
the on- call local P/Way supervisor, the other a bridge examiner, both from
the maintenance contractor. They each assess their relevant aspects (ie the
bridge examiner the structure and the P/Way supervisor the track). Following
this, a TSR may or may not be implemented, either for the condition of the
track, the condition of the bridge or both.

TSR boards are set out in the cess by the local P/Way gang under instruction
from the relevant person of authority (see above). They are arranged in the
direction of traffic as follows:

WARNING BOARD
+
braking distance
+
SPEED BOARD (often referred to as the C board)
+
length of TSR (in the case of a bridge strike, probably the length of the
bridge)
+
TERMINATION BOARD (T board)

Boards are reflective reflective signs, the warning board having the speed
limitation (5, 20, 50 etc.) on a square board with a seperate rectangular
board below it showing two white reflective circles (commonly referred to as
a fishtail). The C board will have the speed limitation on a square
board, the T board a letter T.

However, there are such things as differential TSRs. This is where the
warning and C boards display two speeds above the fishtail. The top speed
will usually be lower and this is the TSR at which locos, bogie stock,
freight trains etc. must travel. The lower speed, which will be higher, is
the speed at which DMUs (and I think parcels trains) must travel. However in
my experience, differential speeds are rarely applied following bridge
strikes. Its usually a blanket (all one speed) TSR of either 5 or 20 mph,
or traffic stopped completely, depending upon the damage to the track and/
or structure.

My first thought when you mentioned the EWS train travelling slower/
stopping than the passengers was that a differential TSR had been applied,
with freight obviously travelling slower. I now think that the more likely
explanation is that either one or both of the examiners had not yet reached
the scene and the signaller was cautioning trains over the section of track.
(This is where the signaller will stop a train at the nearest controllable
signal in advance of the incident and warn the driver to pass the relevant
stratch at caution). However, the definition of caution from one driver,
p/way man, signaller etc. to another is often blurred (I believe the Rule
Book definition can be vague too but I dont have one to hand to check),
hence the probable reason all the trains you witnessed passed over the
bridge at different speeds.

Again, I am not totally sure of that last paragraph as the usual situation
is for a line to be stopped completely until the examiners arrive on the
scene and pass it fit for traffic at whatever speed. Perhaps someone more
informed may enlighten us of the nature of the incident?

db.



Neil McDonald wrote in message
news:1082235505.52128.1@iris.uk.clara.net...

On Sat, 17 Apr 2004 22:21:46 GMT, Dirk Belcher
wrote:

Strictly speaking, an ESR rather than a TSR may be imposed after a
bridge strike, as its unplanned, not in the W.O.N. and drivers will
have had little warning of it. A Dalek is usually placed well ahead
of the restriction to warn drivers of its existence.

Paul Harley

Paul Harley wrote in message
news:9tg3801e9465memgo8cejofldi5gi6cfm8@4ax.com...

I agree completely, thanks for pointing that out.

However, the OP asked about TSRs (not ESRs) but I should have pointed out
that a speed restriction following an incident is an ESR rather than a TSR.
Keeps people on their toes though!

An ESR is still a TSR but I understand the differentiation you are trying to
make.

db.

- And on Sat, 17 Apr 2004 21:56:47 +0100, it was spake thus
said in message Neil McDonald
:


Some excellent info already posted, you could also take a look at
http://www.devilsguide.com/back.asp?page=spe00 00.htm§ion=Operating%20rules
or the www.rssb.co.uk for some more info about them
--
Nick
All my own comments !
Worked on the Signalling in the North East since 1983 !
http://www.whelan.me.uk
Also nickw7coc on both Yahoo Messenger & on MSN Messenger

When a bridge strike occurs (or more importantly is reported) the
line(s) is(are) blocked by the signaller. What happens next depends upon
who arrives at the scene first.

In the area that I work it is paged out to both Network Rail staff and
to the maintenance contractor (IMC). The IMCs control has also been
informed by NWR control and they have the pway section manager attend
to inspect the line. Anyone closer who is also qualified may also
attend, hence it being paged out as it might be that someone is much
closer. The NWR Mobile Operations Manager (MOM) is directed to the
location (if theyre not at another incident) too by NWR control, as
they too are qualified to re-open the line.

There are two levels of qualification for raising linespeed:

Bridge Strike Nominee (BSN) 1 who can raise the speed to 5mph, which the
signaller would then inform each driver of. This at least gets the
trains moving (although at 5mph). Before this the BSN1 person will have
inspected the bridge, abutments and track for signs of damage and there
are defined amounts of damage that are acceptable for 5mph, i.e. no
deformation of steel elemts within the bridge. If it doesnt meet these
criteria then the line stays blocked.

BSN2 allows linespeed to be resumed following inspection.

In cases of major damage then a structures engineer is called to site,
but the majority of bridge strikes inflict little or no damage.

There are a number of bridges that have been given automatic 5mph
dispensation, as they are so heavy that it is highly improbable that a
vehicle would have caused any significant damage. A large masonary arch
bridge would be an example of this, as there is just so much mass to the
bridge that a vehicle would barely damage it. Each bridge will have been
individually assed for this criteria. NWR control have a list of these
bridges and implement the 5mph dispensation via the signaller.

On Sat, 17 Apr 2004 22:21:46 GMT someone who may be Dirk Belcher
wrote this:-


Im fascinated that the term is still used, as it must be nearly
three decades since such boards displayed a C rather then the
speed limit.


--
David Hansen, Edinburgh | PGP email preferred-key number F566DA0E
I will always explain revoked keys, unless the UK government
prevents me using the RIP Act 2000.

Dirk Belcher wrote in message
news: 5igc.151784$gA5.1819833@attbi s03...

The lifting arms of a skip lorry struck the bridge (possibly the underside
of the bridge) jamming the lorry just after 7am. There are 2 bridges side by
side - one carries the ECML, the other (formerly part of the Abbeyhill loop
on the South Sub) the line to the rubbish loading station at Powderhall.
Not sure which one the lorry was actually stuck at. The EWS driver stopped
just short of the bridge on the Abbeyhill loop line - no signal there, but
that is the only train to use that line, he had obviously been told about it
and was stationary for about 10 minutes before proceeding very slowly - the
signal protecting his junction onto the ECML is about the length of the
train beyond the bridge. The ECML trains continued to run, but at varying
speeds. The ECML speeds were back to normal by early afternoon. I think
possibly the problem has been on the secondary line, but the close proximity
of the bridges has caused the reduced speed on the ECML bridge until the
all-clear was given.

--
Neil McD.