https://golbornevintageradio.co.uk/forum/ Fri, 17 Apr 2026 03:18:42 +0000 MyBB https://golbornevintageradio.co.uk/forum/showthread.php?tid=7263 Wed, 26 Dec 2018 00:59:46 +0000 Refugee]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=7263 It is a nice bit of vintage film on the rails.
https://player.bfi.org.uk/free/film/watc...pTBbHjpSgU]]> It is a nice bit of vintage film on the rails.
https://player.bfi.org.uk/free/film/watc...pTBbHjpSgU]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2245 Tue, 26 Jun 2012 23:46:23 +0000 glowinganode]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2245 this fascinating document.
A little heavy going, mainly due to the sheer amount of detail.
Happy reading,
Rob.]]> this fascinating document.
A little heavy going, mainly due to the sheer amount of detail.
Happy reading,
Rob.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2236 Sat, 23 Jun 2012 22:39:06 +0000 glowinganode]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2236 http://www.youtube.com/watch?v=1vk8gEHnJ...ure=g-vrec
Cheers,
Rob.]]> http://www.youtube.com/watch?v=1vk8gEHnJ...ure=g-vrec
Cheers,
Rob.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2224 Thu, 21 Jun 2012 18:24:49 +0000 ed731pdh]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2224

  D-70006-Sht_31.pdf (Size: 127.22 KB / Downloads: 63) ]]>

  D-70006-Sht_31.pdf (Size: 127.22 KB / Downloads: 63) ]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2219 Thu, 21 Jun 2012 07:58:57 +0000 glowinganode]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=2219 Were M-G sets ever used?
Cheers,
Rob.]]> Were M-G sets ever used?
Cheers,
Rob.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=1621 Sun, 18 Dec 2011 15:39:33 +0000 dennishoy]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=1621 I don't want to turn this into a 'train-spotting' thread, nor make it too complex and boring.

Today, I will try to describe the basic design of the power circuits on the locomotive.

When running as an electric locomotive, 73140 takes power from a conductor rail through collector shoes. The voltage varies, but is usually around 850V and the current can be 2000A when starting with a heavy load. A 110V supply for the control equipment is supplied from a motor-generator set which is simply a machine comprising of 850V motor and 110V generator wound on the same armature, but with separate commutators at each end.

When running as a diesel-electric locomotive, the collector shoes are retracted and a diesel engine drives a pair of generators. A 'main generator' supplies current for the traction motors and an 'auxiliary generator' provides 110V DC for the control equipment. This assembly is called the power unit.

73140 has the power unit at one end of the locomotive and the electrical control equipment at the other for two reasons. The first is to keep high voltage equipment away from anyone servicing the diesel engine and the other is to prevent dirt and oil contamination of the electrical equipment.

73140 has four wheelsets (a wheelset is an axle with a wheel at each end). There are two wheelsets under each bogie and a bogie under each end of the locomotive. All the axles carry a traction motor between the wheels (normally hidden from view). The two motors under each bogie are permanently connected in parallel.

Under electric operation, the traction motors are initially connected as two series groups of two motors in parallel. As the locomotive speed increases, the motors are connected in parallel. The voltage across the motors is increased by short-circuiting sections of the main starting resistors under the control of an electrically-driven camshaft. Once maximum speed has been attained, a further increase in motor speed is obtained by four stages of weak field diversion under the control on another electrically-driven camshaft. Inductive shunts are connected in series with the field divert resistors to prevent damage caused by motor flashovers.

Under diesel operation, current for the traction motors is obtained from the main generator (driven directly from the engine crankshaft). The generator output is varied by a combination of engine speed and control of generator field excitation by a electrically-driven load regulator. The starting resistors are therefore not required under diesel operation until the motors are re-grouped from series to parallel. Weak field diversion operates using the camshaft, but this time under the control of the diesel engine load regulator.

All power circuits are connected using electro-pneumatic line breakers rated at 2000A DC current at 1000V.
(no, you definitely do not want to stand near them or look at them when they operate under full load).

That is probably enough said about the power circuits for now.


It may be easier to consider the operation of the power circuits in a more familiar form......

Take four (say 12V) DC motors and connect them permanently as two parallel pairs.
Then connect the two parallel pairs in series.
Put some resistance in series with the motors and apply 12V.
Progressively short out the resistance in stages until it is zero and the motors are running at half speed (6V across each pair of motors).
Reconnect the two parallel pairs in parallel.
Put the resistance back in and reconnect 12V.
Progressively short out the resistance in stages until it is zero and the motors are running at full speed (12V across each pair of motors).
The motors cannot run any faster as it stands.
Now divert some of the field current by putting some resistance across the field of each motor i.e. weak fielding the motors.
The motors will now run faster.
Now further weaken the field by putting additonal resistances across the field of each motor until four stages of weak field have been applied.
The motors are now running at maximum speed in full weak field, and the locomotive will be running at maximum speed.

Perhaps the attached power schematic will help too....
The line breakers to connect the motors close in sequence L1, L3, JR, ISC and L2 under electric operation and L7, L5, L6, ISC, J and L2 under diesel operation.
Some clever interlocking prevents faulty operation such as connecting the output of the main generator to the live rail! Ouch.

OL1, OL2 are overload relays, CBR is the current balance relay to ensure the current though M1+M2 = the current through M2+M4, and WSR are wheelslip relays to prevent wheel spinning. All to be explained next time.

Logically, when moving in a forward direction, the front (or leading) half of the locomotive will be moving forwards, but the rear (or trailing) half will be travelling in reverse. This is a bit confusing until you understand the concept. The direction of travel is changed by reversing the field current on all four traction motors (while the locomotive is stationary of course!).

I shall try and describe some of the control equipment next time; sufficient to say that this has to be complex by it's very nature.

  Sht95.pdf (Size: 164.35 KB / Downloads: 70) ]]> I don't want to turn this into a 'train-spotting' thread, nor make it too complex and boring.

Today, I will try to describe the basic design of the power circuits on the locomotive.

When running as an electric locomotive, 73140 takes power from a conductor rail through collector shoes. The voltage varies, but is usually around 850V and the current can be 2000A when starting with a heavy load. A 110V supply for the control equipment is supplied from a motor-generator set which is simply a machine comprising of 850V motor and 110V generator wound on the same armature, but with separate commutators at each end.

When running as a diesel-electric locomotive, the collector shoes are retracted and a diesel engine drives a pair of generators. A 'main generator' supplies current for the traction motors and an 'auxiliary generator' provides 110V DC for the control equipment. This assembly is called the power unit.

73140 has the power unit at one end of the locomotive and the electrical control equipment at the other for two reasons. The first is to keep high voltage equipment away from anyone servicing the diesel engine and the other is to prevent dirt and oil contamination of the electrical equipment.

73140 has four wheelsets (a wheelset is an axle with a wheel at each end). There are two wheelsets under each bogie and a bogie under each end of the locomotive. All the axles carry a traction motor between the wheels (normally hidden from view). The two motors under each bogie are permanently connected in parallel.

Under electric operation, the traction motors are initially connected as two series groups of two motors in parallel. As the locomotive speed increases, the motors are connected in parallel. The voltage across the motors is increased by short-circuiting sections of the main starting resistors under the control of an electrically-driven camshaft. Once maximum speed has been attained, a further increase in motor speed is obtained by four stages of weak field diversion under the control on another electrically-driven camshaft. Inductive shunts are connected in series with the field divert resistors to prevent damage caused by motor flashovers.

Under diesel operation, current for the traction motors is obtained from the main generator (driven directly from the engine crankshaft). The generator output is varied by a combination of engine speed and control of generator field excitation by a electrically-driven load regulator. The starting resistors are therefore not required under diesel operation until the motors are re-grouped from series to parallel. Weak field diversion operates using the camshaft, but this time under the control of the diesel engine load regulator.

All power circuits are connected using electro-pneumatic line breakers rated at 2000A DC current at 1000V.
(no, you definitely do not want to stand near them or look at them when they operate under full load).

That is probably enough said about the power circuits for now.


It may be easier to consider the operation of the power circuits in a more familiar form......

Take four (say 12V) DC motors and connect them permanently as two parallel pairs.
Then connect the two parallel pairs in series.
Put some resistance in series with the motors and apply 12V.
Progressively short out the resistance in stages until it is zero and the motors are running at half speed (6V across each pair of motors).
Reconnect the two parallel pairs in parallel.
Put the resistance back in and reconnect 12V.
Progressively short out the resistance in stages until it is zero and the motors are running at full speed (12V across each pair of motors).
The motors cannot run any faster as it stands.
Now divert some of the field current by putting some resistance across the field of each motor i.e. weak fielding the motors.
The motors will now run faster.
Now further weaken the field by putting additonal resistances across the field of each motor until four stages of weak field have been applied.
The motors are now running at maximum speed in full weak field, and the locomotive will be running at maximum speed.

Perhaps the attached power schematic will help too....
The line breakers to connect the motors close in sequence L1, L3, JR, ISC and L2 under electric operation and L7, L5, L6, ISC, J and L2 under diesel operation.
Some clever interlocking prevents faulty operation such as connecting the output of the main generator to the live rail! Ouch.

OL1, OL2 are overload relays, CBR is the current balance relay to ensure the current though M1+M2 = the current through M2+M4, and WSR are wheelslip relays to prevent wheel spinning. All to be explained next time.

Logically, when moving in a forward direction, the front (or leading) half of the locomotive will be moving forwards, but the rear (or trailing) half will be travelling in reverse. This is a bit confusing until you understand the concept. The direction of travel is changed by reversing the field current on all four traction motors (while the locomotive is stationary of course!).

I shall try and describe some of the control equipment next time; sufficient to say that this has to be complex by it's very nature.

  Sht95.pdf (Size: 164.35 KB / Downloads: 70) ]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=1617 Sat, 17 Dec 2011 18:00:58 +0000 dennishoy]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=1617 The railway jargon will be kept to a minimum and it is hoped this thread will build up over time and become interesting reading for those who would like to know a little more about the subject.

I will need to start with a brief history....
Locomotive 73140 was one of 49 electro-diesel locomotives built between 1962 and 1967 for British Railways. The first six prototypes were built at BR Eastleigh Works on the Southern Region and the production batch of 43 were built at the English Electric Vulcan Foundry at Newton-le-Willows.

This class of locomotive is unusual, in that it is primarily an electric locomotive drawing current from the Southern Region third rail system at 850 Volt DC, but is additionally fitted with a 600hp diesel engine and DC generator to allow it to work on non-electrifed lines.

The original numbering system was E6001 to E6049 in build sequence. The class was renumbered in the early 1970s and E6047 became 73140 under the new system. Our locomotive was almost at the end of the build sequence and entered service in late 1966.

73140 was withdrawn from service in 1998 and stored with many others until 2001 when it was offered for sale for scrap by competitive tender. Paul Hubbard and I had been actively involved since 1996 in running 73003, an early member of the class built in 1962 and had gained a lot of experience over the years. We decided we would like to buy a later example, so we looked over all the locomotives offered and selected 73140 as being fairly complete and in best overall condition. Our offer by tender was accepted (we outbid the scrapman) and all 77 tons of 73140 was taken away by road on a lorry to be restored to working order.

The locomotive now resides on the Spa Valley Railway at Tunbridge Wells in Kent where Paul and I have maintained and run it over the last 10 years. We have restored it to original condition as E6047 in the British Railways blue colour scheme. Visitors from the Forum will be most welcome to visit us and will be able to have a close look at the locomotive internals if they wish (assuming one of us is on site).

Paul and I hope to add regular posts to this thread and answer any questions folk may ask.

A link to the host railway is here:
http://www.spavalleyrailway.co.uk/SpaCls73_04.htm

Some pictures are here:
http://www.preserved-diesels.co.uk/engin..._index.htm

The next installment will attempt to describe the electrical workings of the locomotive in a bit more detail.]]> The railway jargon will be kept to a minimum and it is hoped this thread will build up over time and become interesting reading for those who would like to know a little more about the subject.

I will need to start with a brief history....
Locomotive 73140 was one of 49 electro-diesel locomotives built between 1962 and 1967 for British Railways. The first six prototypes were built at BR Eastleigh Works on the Southern Region and the production batch of 43 were built at the English Electric Vulcan Foundry at Newton-le-Willows.

This class of locomotive is unusual, in that it is primarily an electric locomotive drawing current from the Southern Region third rail system at 850 Volt DC, but is additionally fitted with a 600hp diesel engine and DC generator to allow it to work on non-electrifed lines.

The original numbering system was E6001 to E6049 in build sequence. The class was renumbered in the early 1970s and E6047 became 73140 under the new system. Our locomotive was almost at the end of the build sequence and entered service in late 1966.

73140 was withdrawn from service in 1998 and stored with many others until 2001 when it was offered for sale for scrap by competitive tender. Paul Hubbard and I had been actively involved since 1996 in running 73003, an early member of the class built in 1962 and had gained a lot of experience over the years. We decided we would like to buy a later example, so we looked over all the locomotives offered and selected 73140 as being fairly complete and in best overall condition. Our offer by tender was accepted (we outbid the scrapman) and all 77 tons of 73140 was taken away by road on a lorry to be restored to working order.

The locomotive now resides on the Spa Valley Railway at Tunbridge Wells in Kent where Paul and I have maintained and run it over the last 10 years. We have restored it to original condition as E6047 in the British Railways blue colour scheme. Visitors from the Forum will be most welcome to visit us and will be able to have a close look at the locomotive internals if they wish (assuming one of us is on site).

Paul and I hope to add regular posts to this thread and answer any questions folk may ask.

A link to the host railway is here:
http://www.spavalleyrailway.co.uk/SpaCls73_04.htm

Some pictures are here:
http://www.preserved-diesels.co.uk/engin..._index.htm

The next installment will attempt to describe the electrical workings of the locomotive in a bit more detail.]]>