Level Crossing abbreviations

[d405]

All this talk of level crossings raises one associated question, as far
as I am concerned:-

Can somebody explain or direct me towards an explanation of the LC
codings that are used. Some are indeed obvious, but I (for one) am at a
loss as to the difference between, e.g. ABCL, AOCL and AOCR.

TIA

[0.7ohm Drop Shunt]

Off the top of my head- -

LC - Level Crossing - basic crossing, maybe fitted with farm style
gates, and phones, or just an old stlye Wooden gated LC
AOCL - Automatic Open Crossing Locally monitered
AOCR - Automatic Open Crossing Remotely monitered (theres only 1 left)
AHBC - Automatic Half Barrier Crossing
AHB-X - Automatic Half Barrier - Bi-Directional operation
MCB1 - Manually Controlled Barriers where the signal/gate box is
adjacent
MCB2 - Manually Controlled Barriers where the signal/gate box is within
a certain distance
MCB3 - Manually Controlled Barriers with CCTV supervision
MWL - Miniature Warning Lights, also known as R/G


Actually Page 53 here has them all
http://www.rgsonline.co.uk/docushare/dsweb/Get/Rail-5103/gn0802.PDF

[Henning Makholm]

Post by 0.7ohm Drop Shunt
AOCL - Automatic Open Crossing Locally monitered
AOCR - Automatic Open Crossing Remotely monitered (theres only 1 left)

What do these mean?

Post by 0.7ohm Drop Shunt
AHBC - Automatic Half Barrier Crossing
AHB-X - Automatic Half Barrier - Bi-Directional operation

What does bi-directional mean? Is it AHBC when the crossing road is a
one-way street? Or is it the trains that go only in one direction?

[0.7ohm Drop Shunt]

Post by Henning Makholm

Post by 0.7ohm Drop Shunt
AOCL - Automatic Open Crossing Locally monitered
AOCR - Automatic Open Crossing Remotely monitered (theres only 1 left)

What do these mean?

AOCL - there are road lights for the car driver, but no barriers at
these crossings.
The Train Driver is shown a white light to prove to him that the road
lights are working. At some modern corssings, he gets a flashing red
aspect if the road lights have not started.

AOCR - An obsolescent type of Automatic Level Crossing, similar to an
AHBC but
without Barriers.

Post by Henning Makholm

Post by 0.7ohm Drop Shunt
AHBC - Automatic Half Barrier Crossing
AHB-X - Automatic Half Barrier - Bi-Directional operation

What does bi-directional mean? Is it AHBC when the crossing road is a
one-way street? Or is it the trains that go only in one direction?

Bi Directional Operation is for the trains, not the cars - the trains
can run "wrong line" at reduced speed (40MPH) and the crossing will
work automatically. If the crossing is not an AHB-X, it requres an
attendant to manually lower the barriers.
This requires "wrong direction treadles" and additional track circuits.

[Henning Makholm]

Post by 0.7ohm Drop Shunt
Bi Directional Operation is for the trains, not the cars - the trains
can run "wrong line" at reduced speed (40MPH) and the crossing will
work automatically.

Ah. I had somehow mentally tuned out the possibility of a level
crossing on a double-track line.

How will a single-track AHB be classified?

[BH Williams]

Post by Henning Makholm

Post by 0.7ohm Drop Shunt
Bi Directional Operation is for the trains, not the cars - the trains
can run "wrong line" at reduced speed (40MPH) and the crossing will
work automatically.

Ah. I had somehow mentally tuned out the possibility of a level
crossing on a double-track line.
How will a single-track AHB be classified?
--
Henning Makholm "En tapper tinsoldat. En dame i
spagat. Du er en lykkelig mand ..."

AHB, I believe.
Brian

[BH Williams]

Post by Henning Makholm

Post by 0.7ohm Drop Shunt
AOCL - Automatic Open Crossing Locally monitered
AOCR - Automatic Open Crossing Remotely monitered (theres only 1 left)

What do these mean?

Post by 0.7ohm Drop Shunt
AHBC - Automatic Half Barrier Crossing
AHB-X - Automatic Half Barrier - Bi-Directional operation

What does bi-directional mean? Is it AHBC when the crossing road is a
one-way street? Or is it the trains that go only in one direction?
--
Henning Makholm # good fish ...
# goodfish, goodfish ...
# good-good FISH! #

Bi-directional (banalise for French readers) means that trains may run in
either direction on either track, rather than following the normal
convention of trains running in one direction only.
Brian

[Grebbsy McLaren]

It was a dark and stormy night when 0.7ohm Drop Shunt
<***@hotmail.com> wrote in article <***@c13g200
0cwb.googlegroups.com>...

Post by 0.7ohm Drop Shunt
Off the top of my head- -
LC - Level Crossing - basic crossing, maybe fitted with farm style
gates, and phones, or just an old stlye Wooden gated LC
AOCL - Automatic Open Crossing Locally monitered
AOCR - Automatic Open Crossing Remotely monitered (theres only 1 left)

Where?

Grebbsy

[0.7ohm Drop Shunt]

Post by Grebbsy McLaren
It was a dark and stormy night when 0.7ohm Drop Shunt
0cwb.googlegroups.com>...

Post by 0.7ohm Drop Shunt
Off the top of my head- -
LC - Level Crossing - basic crossing, maybe fitted with farm style
gates, and phones, or just an old stlye Wooden gated LC
AOCL - Automatic Open Crossing Locally monitered
AOCR - Automatic Open Crossing Remotely monitered (theres only 1 left)

Where?

Its on the Scottish Region somewhere. I'll look back course notes, and
try and find out where. I might have written it down.

[Brimstone]

TIA

What's TIA?

;-)

[BH Williams]

Post by Brimstone

TIA

What's TIA?
;-)

Either 'thanks in advance' or 'trans-ischaemic attack', depending who's
asking.
Brian

[d405]

Post by BH Williams

Post by Brimstone

TIA

What's TIA?
;-)

Either 'thanks in advance' or 'trans-ischaemic attack', depending who's
asking.
Brian

I meant the former!

[Peter Masson]

Post by d405
Can somebody explain or direct me towards an explanation of the LC
codings that are used. Some are indeed obvious, but I (for one) am at a
loss as to the difference between, e.g. ABCL, AOCL and AOCR.

If you want a full explanation of the different types of crossing there's
one in
http://www.rssb.co.uk/pdf/reports/Road%20Vehicle%20Level%20Crossings%20Special%20Topic%20Report.pdf
But basically:
MCG - Manual Controlled Gates, which could be anything from gates opened by
trainmen on a minor branch, a traditional crossing worked by a crossing
keeper, or gates opened by the signaller using a big wheel in the adjacent
signalbox.
MCB - Manual Controlled barriers, worked from an adjoining signalbox, or
remotely using closed circuit TV (CCTV). These will have barriers that close
right across the road.
AHB - Automatic half barriers. Work automatically when the train strikes in
27+ seconds away. There is a telephone link to a signalbox, and the
signaller has equipment to confirm that the crossing works properly and a
controlled signal (may be some way away from the crossing) to stop trains -
but it's too late if he is only notified of a problem when the train strikes
in.
ABCL - Automatic barrier crossing, locally monitored. Looks similar to an
AHB, but a white flashing light is shown to the train driver if the crossing
is working properly, and the train must stop if it isn't.
AOCR - Automatic open crossing, remotely monitored. Like an AHB without the
barriers. There's only one of these.
AOCL - Automatic open crossing, locally monitored. Like an ABCL without the
barriers, only lights to stop road traffic. No telephone to the signalbox.
UWC - User worked crossing (only on private roads, farm crossings, etc). May
have lights, miniature red and green lights, a telephone, or just signs
'Stop Look Listen.'
Peter

[Capt. Flack]

Post by Peter Masson
AHB - Automatic half barriers. Work automatically when the train strikes in
27+ seconds away. There is a telephone link to a signalbox, and the
signaller has equipment to confirm that the crossing works properly and a
controlled signal (may be some way away from the crossing) to stop trains -
but it's too late if he is only notified of a problem when the train strikes
in.

The `some way away from the xing' can be miles. Example Purton Collins Lane
AHB between Kemble and Swindon, you pass over Minety xing (MG) which is
protected by signals, then Purton Collins Lane AHB is more than 5 miles
away, there are no intermediate signals. Incidentally, there was a suicide
there a few months ago, the guy just crawled onto the track as the barriers
came down.

[Clive D. W. Feather]

Post by d405
Can somebody explain or direct me towards an explanation of the LC
codings that are used. Some are indeed obvious, but I (for one) am at
a loss as to the difference between, e.g. ABCL, AOCL and AOCR.

Crossings interlocked with the signalling:

MG = manually operated gates
MCB = manually controlled barriers
MCB(CCTV) = ditto with CCTV rather than direct observation

Both MG and MCB may be operated by a signaller at the crossing or by one
at a nearby gate or signal box but still observing the crossing
directly.

Crossings not interlocked with the signalling, but where a remote
signaller gets an alert of any failure:

AHB = automatic half barrier
AOCR = automatic open crossing (remotely monitored)

Crossings not interlocked with the signalling but where the train driver
must check the crossing equipment has operated (indicated by a flashing
white light):

ABCL = automatic barrier crossing (locally monitored)
AOCL = automatic open crossing (locally monitored)

Crossings not interlocked with the signalling or monitored in any way:

UWC = user worked crossing
UWC(R/G) = user worked crossing (miniature red/green warning lights)
UWC(T) = user worked crossing (telephone)
OC = occupation crossing
FP = footpath crossing

UWCs are on roads, OCs run between farmers' fields.

I've sometimes seen "MWL" written instead of "R/G".

[0.7ohm Drop Shunt]

Post by Clive D. W. Feather

Post by d405
Can somebody explain or direct me towards an explanation of the LC
codings that are used. Some are indeed obvious, but I (for one) am at
a loss as to the difference between, e.g. ABCL, AOCL and AOCR.

MG = manually operated gates
MCB = manually controlled barriers
MCB(CCTV) = ditto with CCTV rather than direct observation
Both MG and MCB may be operated by a signaller at the crossing or by one
at a nearby gate or signal box but still observing the crossing
directly.
Crossings not interlocked with the signalling, but where a remote
AHB = automatic half barrier
AOCR = automatic open crossing (remotely monitored)
Crossings not interlocked with the signalling but where the train driver
must check the crossing equipment has operated (indicated by a

flashing

Post by Clive D. W. Feather
ABCL = automatic barrier crossing (locally monitored)
AOCL = automatic open crossing (locally monitored)
UWC = user worked crossing
UWC(R/G) = user worked crossing (miniature red/green warning lights)
UWC(T) = user worked crossing (telephone)
OC = occupation crossing
FP = footpath crossing
UWCs are on roads, OCs run between farmers' fields.
I've sometimes seen "MWL" written instead of "R/G".
--

<http://www.davros.org>
Thats the latest standard, however the older abreviations are still out
there, either in the wiring diagrams, or on signal box/centre panels
and indications.