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| AYLESBURY - CALVERT TOKEN 10/07/2013 at 09:42 #46879 | |
jc92
3685 posts 
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wouldnt it make sense for the section signal at aylesbury vale to be locked at danger unless the system detects a token is out, in order to prevent situations (however unlikely) as this? certainly at Ambergate and Woodburn jcn, the signals allowing exit from the single line require the token to be replaced before they clear for the inverse reason, ie trains failing to surrender the token. "We don't stop camborne wednesdays" Log in to reply |
| AYLESBURY - CALVERT TOKEN 10/07/2013 at 10:36 #46887 | |
kbarber
1742 posts |
" said:In the old days, with a signal box at either end of the section, the S & T Linesman would visit the box with the excess tokens (or train staffs), unlock the machine and remove some tokens. The signaller would check the number of tokens removed, and an entry made in the train register signed by the linesman & counter signed by the signaller. At the receiving box the linesman unlocked the machine, the tokens were placed in the machine, and a corresponding entry was made in the train register, again signed by both persons. If I recall the regs correctly there was also a special token register that the lineman carried; as well as filling in the TRB, the number transferred was entered in the register and countersigned by the signalman. The bobby at the receiving end then counted them in and countersigned the token register again (as well as the entry in his own TRB). The tokens in transit were carried in a special (locked? sealed?) bag and, like the magazine, did not constiture authority to enter the single line section. I'm not so sure the Stationmaster wasn't required to be present overseeing proceedings as well, in the days when such personages existed. Log in to reply The following user said thank you: GeoffM |
| AYLESBURY - CALVERT TOKEN 10/07/2013 at 14:39 #46910 | |
GeoffM
6376 posts
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" said:wouldnt it make sense for the section signal at aylesbury vale to be locked at danger unless the system detects a token is out, in order to prevent situations (however unlikely) as this?It is interlocked. Problem is it's too late by then. Can't lock the previous signals because that would block passenger trains to AVP. SimSig Boss Log in to reply |
| AYLESBURY - CALVERT TOKEN 10/07/2013 at 15:15 #46914 | |
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jc92
3685 posts
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" said:" said:Ah! i havent had a chance to actually send anything to Claydon LNE yet, but inferred from the original post there was no protection, I spose having to set a through route onto the single line (bypassing AVPs starter)which doesnt release the loop or main until a token is out would be a way of overcoming that.wouldnt it make sense for the section signal at aylesbury vale to be locked at danger unless the system detects a token is out, in order to prevent situations (however unlikely) as this?It is interlocked. Problem is it's too late by then. Can't lock the previous signals because that would block passenger trains to AVP. "We don't stop camborne wednesdays" Log in to reply |
| AYLESBURY - CALVERT TOKEN 10/07/2013 at 16:17 #46919 | |
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Cedric
46 posts |
Thanks for your helpful replies to my original post. I have now sent a train in the opposite direction (from Aylesbury to Calvert) and the situation has righted itself. Unorthodox but it worked. I seem to have unintentionally started quite a string about balancing tokens where there are an unequal number of trains running in either direction on a single line. It's a long time since I worked on an operational railway, but I have seen both S&T linesman signing for and transferring tokens through the section as a balancing exercise (Ash Vale Jn to Frimley Jn pre Feltham re-signalling when the section was controlled by a Tyers No 6 Tablet) and on the Talyllyn Railway where the Wharf Pendre Section was Miniature Electric Train Staff (pre about 1972) and the instruments were fitted with a carrier interlocked with the instrument as described in one of the posts. Incidentally, I remember spending an evening in Aylesbury South box in the early 1970S. If I remember rightly there was a full-sized Electric Train Staff for the Claydon Section, with a remote instrument on the platform so that platform staff could hand the staff to and from the driver without going to the box? The section round to Princes Risborough was a more standard Western-style Electric Key Token instrument. It was a long time ago and memory fades, but it was a most enjoyable evening. Cedric Log in to reply |
| AYLESBURY - CALVERT TOKEN 10/07/2013 at 20:02 #46937 | |
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Stephen Fulcher
2078 posts
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" said:" said:I have personally transferred tokens around this very system both before and since the Aylesbury Vale Parkway modifications." said:Aha, that makes sense - the diagrams state "Balancing magazine to be provided". Thanks.Where balancing happens regularly, the machines are adapted to take a carrier. Tokens can be moved into or out of the carrier from the magazine but can't otherwise be got out of that hole. Similarly, the hatch on the carrier only opens when it's connected to an appropriate machine. Tokens in a carrier do *NOT* grant authority to proceed on the line. Essentially you can remove any even number of tokens from the system and it will still work for the passage of trains with those tokens out. I believe is is technically allowable to mechanically release tokens for transfer with a train in the section, although I personally would never entertain the idea as removing an odd number would put the system back in phase and allow another token to be released for another train with the first one still in there. What was the "norm" was to electrically release the first token to prove the section clear, destroy the section signal release by clearing the signal and then replacing it, and then mechanically release the required number to be transferred, taking care to ensure we were left with an even number out of the machine. These were then inserted in the normal way into the receiving instrument, and the system tested to ensure a release was possible. A log is also kept of any such transfers. The balancing magazines installed at the two instruments at Aylesbury North is operated by suitably trained Mobile Operations Managers as opposed to S&T Technicians and tokens are transferred by a separate "aperture" in the side of the instrument rather than the normal commutator at the top. This method of transfer in no way affects the integrity of the system. Any number of tokens can be transferred with no risk to train running, and the tokens are locked into a special carrier whilst being transferred between instruments, and cannot be removed unless the carrier is connected to the transfer aperture of an instrument of the appropriate configuration. Transfers involving the instruments at Claydon L&NE Junction Signal Box and Calvert Shunters Cabin have to be done in the traditional manner as they are not fitted with the balancing magazine system. Log in to reply The following users said thank you: BarryM, kbarber, guyh |
| AYLESBURY - CALVERT TOKEN 11/07/2013 at 11:15 #46987 | |
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Haraubrad
103 posts |
I would imagine if no token working by pilotman is needed. Aubrey Log in to reply |
| AYLESBURY - CALVERT TOKEN 11/07/2013 at 12:13 #46989 | |
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Stephen Fulcher
2078 posts
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Working by pilotman would be required if no token was available, however in practice this would be of little benefit as more-or-less all of the trains on the line are booked in Calvert, which requires the token to release the Ground Frames. When the cables went missing, someone from the S&T had to manually release a token for the Pilotman to carry so that access to the sidings was possible. Log in to reply |