A day in the life of a Locking Team

[00:00:04]In today's video, we're going to join the London Northwestern maintainers, installers, and locking testers on the locking side of the S&T.

[00:00:13]These look after the mechanical interlocking of all the signal boxes around the London Northwestern region.

[00:00:18]And today we're going to visit Warrington Arpley, a mechanical signal box that controls the freight movements on the previous mainline route between Liverpool and Manchester.

[00:00:28]The signal box itself is a London Northwestern design that controls a mix of both semaphores, upper quadrant, and color light signals, which are slotted to the Preston power signal box.

[00:00:40]The box is used for freight running around movements and getting stuff on and off the West Coast mainline and the sidings.

[00:00:47]So anyway, let's jump into the actual locking box and see what the teams actually have to do on these two-day blockades where they have control of the signal box to undertake the locking tests.

[00:00:57]So to downstairs in the locking room, the first job after having the safety brief is to remove the locking tray covers and also the holding down bars across the tappets.

[00:01:07]With this being done, this now requires a full correlation check between the diagrams and the actual locking to make sure that there's no extra locking or locking that shouldn't be there and also that everything is as matching the plan before it's all removed, taken outside, and cleaned, which you'll see in the video.

[00:01:26]Now listen carefully to what the locking fitters say next. They have their own special language, a code between themselves so that they understand what one person at one end of the frame is saying to the locking tester who's checking the plans. So just listen carefully.

[00:01:39]Correct. And you've got You've got like a fish plate on top from Just bear with me there. That's on the high side of 18.

[00:01:55]Fixed lock.

[00:01:58]Top from, yeah.

[00:02:02]So, I'm guessing you've got a interesting half moon, yeah, kind of piece. So, it's a condition piece, so We'll come back to this half moon piece in a minute as Ryan explains its purpose.

[00:02:18]Top from, so we're outside of 27. Yeah.

[00:02:23]Yeah, it's attached to top from. Yeah. And there's a stud top near.

[00:02:34]Uh, just bear with me.

[00:02:38]Yeah.

[00:02:40]I'm near fixed lock middle of the way, correct? North [snorts] side of 28.

[00:02:47]Each member of the locking team has a go at their own section of the frame repeating the information back to the locking tester so that everyone gets a chance to do this testing. And you'll see later in the video, even the trainee gets to learn some of this as well. So, it's keeping that knowledge going forward.

[00:03:03]Now, we get a rare chance now to have a look at an in-depth piece of mechanical locking called conditional locking. But I'll let Ryan take us forward on that and explain exactly what this is and how this works.

[00:03:14]Thanks, Don.

[00:03:15]What we're looking at here is a really clever piece of mechanical interlocking design on a London Northwestern tappet frame.

[00:03:23]The way conditional locking is achieved on this frame is through a component we call a half moon, which acts as a pivot point.

[00:03:32]In this example, we've got 26 locking 39 both ways when 27 is reversed.

[00:03:40]Now, with 27 in the normal position, there is a small relief cut into the tappet of 27.

[00:03:47]That relief allows the half moon or pivot to sit into it giving it just enough clearance so that when 26 or 39 are operated, they don't apply any locking.

[00:04:00]This is what we call the free move, and it allows 26 and 39 to operate independently while 27 is normal.

[00:04:11]Once 27 is reversed, that relief disappears.

[00:04:15]The half moon now sits against the full flat face of the tappet, which then applies the condition.

[00:04:22]That allows the half moon to move through its full range and operate the locking, which gives us the condition 26 locks 39 both ways when 27 is reversed.

[00:04:34]Mechanically, the lock on 26 connects to the top of the half moon via riveted link and bar with a stud.

[00:04:43]The stud engages into the top of the pivot.

[00:04:46]At the bottom of the half moon, a riveted nib or stud connects to another bar, which then links through to the lock on 39's tappet, which completes the condition.

[00:04:59]That's the actual working condition you're seeing here.

[00:05:03]The counter condition, our condition holding, isn't visible in this view, but that is achieved by 26 locking 27 both ways.

[00:05:13]For this system to work properly, the bars must always be symmetrical.

[00:05:17]So, the top near with top far or bottom near with bottom far, otherwise, the pivot won't behave as intended.

[00:05:27]This method was later superseded by bridge and slide arrangements with overshot locks, but the half moon design is still a brilliant example of mechanical ingenuity.

[00:05:39]It's simple, effective, and honestly, it shows just how clever the engineers behind these systems really were.

[00:05:48]And now we can actually see that in operation as the levers are tried upstairs and we test the locking itself.

[00:05:56]What we're looking at here is a short test demonstrating the action of the pivot in relation to the condition 26 locking 39 both ways when 27 is reversed.

[00:06:09]We start by proving the freedom of 26 and 39 with 27 in the normal position.

[00:06:16]The relief notch cut into 27's tappet allows the half moon to sit in, which means no locking is applied.

[00:06:26]First, you'll see me pull 26 with the half moon engaging into that relief.

[00:06:31]Off camera, I also pull 39 to confirm that both levers are free and operating independently while 27 is normal.

[00:06:42]I also check that I can't reverse 27 in this state.

[00:06:46]That forms part of the condition holding, although this isn't a full test, just part of the overall picture.

[00:06:55]Next, I return 26 and 39 to normal and then reverse 27.

[00:07:01]This removes the relief notch and applies the condition.

[00:07:05]With 27 reversed, the condition is now active.

[00:07:09]26 locks 39 both ways.

[00:07:12]I pull 26 reverse and then attempt to pull 39, but the lock is now applied and 39 is held.

[00:07:21]While in this state, I also check that 27 can't be moved, confirming the condition is holding.

[00:07:29]I then check the back lock, making sure I can't return 39 until 26 is first been restored to normal.

[00:07:37]After that, I confirm that 27 can't be returned until both 26 and 29 are fully normal.

[00:07:46]Finally, I repeat the process in reverse.

[00:07:49]I pull 27, then 39 reverse, and then 26 reverse, confirming that 26 also locks 39 in a reverse position.

[00:08:02]This demonstrates that 26 locks 39 both ways when 27 is reversed.

[00:08:09]What you're seeing here isn't actually a complete test of this locking function.

[00:08:13]Conditional locking requires much more in-depth testing, especially where multiple conditions are involved.

[00:08:20]So, with everything checked now to the drawings, the next step is to clean out the trays, give everything a good sand and rub down, check all the locking, make sure that everything is still tight and that nothing is loose. And some of these bars are the full length of the locking frame, so we're required to take it out the door very carefully with whole groups supporting the bars as they go.

[00:08:43]And of course, the steps are in the way as well. So, this needs to all be factored into the account of how the job is done.

[00:08:50]So, we where we were up to now, we were up to yesterday. We're working on channel C and D so far this morning. As you can see, we've ticked out channel D.

[00:09:00]We've crossed it back in. So, lads at the minute, you've ticked out channel C, they've got the bar out, they're checking the locks, securing C, seeing if any need replacing, they're cleaning it up, tidying it up, repairing any anomalies, shall we say.

[00:09:20]The way the diagram reads, as I've already said, tray one, A B C D. Got the lever numbers at the top.

[00:09:28]1 to 54 in this instance, and it's done in a grid system like that.

[00:09:34]So, if you look at let's say channel eight for an example.

[00:09:40]You've got the top there. Yeah.

[00:09:44]Bottom there. Yes.

[00:09:46]Top middle. Yeah.

[00:09:49]Bottom front. Yeah.

[00:09:51]Top front. Yeah.

[00:09:53]Now, we decided on this terminology because I obviously I know there'll be some people that will say, "Oh, that's bar number blah blah bar number." We decided on this because not everyone is the same and these points are the same.

[00:10:04]This is the terminology we agreed on and it's simpler for everyone. So, people get sometimes get confused cuz you'd expect if you were doing, let's say, bar 1 2 3 4 and 5, a lot of people would think, "Oh, well, the top three must be 1 2 and 3." But, it's not the case. So, it's a better way, in my opinion, of explaining it.

[00:10:26]So, let's say they're calling it out.

[00:10:30]Uh they'd they'd be a I'd be here ticking the sheet. They'd be a leaving number nine and say, "Ryan, there's a fixed lock low side, which is the left of nine."

[00:10:40]Yes.

[00:10:41]I'd look on my diagram. I can see that this black spot, which denotes um a a lock, like a a lock and a converse lock. Yes.

[00:10:53]When it's a clear circle, it's a release lock. Yeah. And it denotes a release.

[00:10:59]So, I check that there. I tick it and I tick the lock in channel eight.

[00:11:07]And I'd know that that where it cuz of where that dot is, that is on the top there. And that confirms that and it's ticked off.

[00:11:14]Um that's very basic what I'm explaining there. So, each symbol has a different meaning.

[00:11:21]Like I said, if it's a colored circle, then that denotes a lock and lock in another.

[00:11:28]Clear circle is a release.

[00:11:31]These little tabs here denote the end of the bar.

[00:11:36]If you follow that along there, there's the other end.

[00:11:40]The little arrows are locks, but they are the actuating locks of the bar. Yeah.

[00:11:47]And the arrow direction denotes which way Yeah. it moves.

[00:11:54]Um what else can I show you on this diagram? It doesn't show any packing bars, but good practice when you're calling marking in and out is that you make a little note of the packing bars and where they come out. Obviously, everything's stamped as well. Yeah. You check that it's correct correctly stamped.

[00:12:10]And it does make things a lot easier going back in and back out.

[00:12:14]Obviously, don't attempt this at home.

[00:12:17]I notice it says stands away. Stands away, yeah. So, any indications like that should be on the diagram. Even with these, there are anomalies that you find cuz they're old drawings, even though they're downloaded from eventually or NRG. Yeah.

[00:12:30]>> There are always anomalies like so last week, I think uh someone called out out something that said, "Oh, where's the lock on 46?" You know, I called that cuz you know, Yeah. it wasn't showing on on No, I'll get that right. It wasn't showing on the diagram, but they called it out. Yes. I'm like, "Well, that shouldn't be there." So, that's part of the checking. So, that's part of the checking, and when I looked at it, it's just a lock that really didn't do anything, and they just left it in probably cuz it was a pain in the bottom to take out.

[00:13:00]>> Yes. Um and you >> Just associate it with the rest of the locking to try and get it out again. You do find that, and then uh we were talking about that interesting little half-moon piece, which on the diagram is there. I don't know if you can see that.

[00:13:12]>> Yes. Yeah.

[00:13:15]And then the the studs that go in there are indicated there.

[00:13:19]Yeah.

[00:13:20]And these studs are indicated with the little dots, and they will be the circles right there. These circles on the bars, which correspond with that. Um Again, if you see So that's a release condition across two channels and we'll show you that a bit later in the afternoon.

[00:13:38]And this is a locking condition because the circles are obviously folding.

[00:13:45]So with everything cleaned now, it's time to get the locking back into the locking trays. And this is a good chance for the trainee wearing the blue hat here to undertake some of the learning process of the locking checking. So in this example, he's shouting out where the locking is being placed, what locks are where, and where in the trays, whether top, bottom, front, middle, etc. And you'll hear him shout that out while he's checked against the diagram by Ryan.

[00:14:13]Okay, middle, front. All right, so on the front on the front side and then it's And then it's on high side and it's nose and near in it. No, near away.

[00:14:32]And then So it's nose. So the nose is closer to uh also away.

[00:14:40]So is it nose away then?

[00:14:42]>> Yeah, nose away. Sorry.

[00:14:45]And then going along Actually young man, so I've got a fixed lock high side of five.

[00:14:52]Uh nose away from the frame on the bottom front.

[00:14:56]Front, front. Yeah.

[00:14:58]Yeah, on the middle on the bottom um is it middle then?

[00:15:05]There's no two bars on the bottom.

[00:15:08]So bottom So bottom near then? Yeah.

[00:15:12]Okay. And then Uh and then there's I don't I don't know what you'd call it, but the the two bars are attached with a four joint Uh on between 18 and 19 Yeah. Yeah. Um Where is this bar?

[00:15:32]Top.

[00:15:33]Uh on the front side. Yeah? Is that Is that it? Yeah? Yeah. Excellent, Callum.

[00:15:38]Good teaching lads as well.

[00:15:41]Now, by now you're probably thinking that the locking testers are well into the day's work, but actually this is only one tray.

[00:15:48]We still have another three trays to do, and there are two days booked to this job. Luckily, Warrington Arpley is a place that is freight only, so a possession of the signal box can actually be gained to allow the staff to undertake all this work. Can you imagine this being done between trains on a very busy junction? This is what the staff have to be able to cope with.

[00:16:10]When I said before that some of the locking bars are the length of the signal box, I was not joking. And this is one out of the two bars I've seen so far that go nearly the full length of the frame, requiring every single member of staff to support the bar so that it is not bent or damaged in any way whilst they navigate around the signal box and the door frame as well.

[00:16:35]So, a final few words from Ryan on what it is to be in the London Northwestern mechanical locking team.

[00:16:42]When we look at this, we need to think about the people who put it in and pay tribute to them because it's an incredible uh mechanical interlocking.

[00:16:52]Tried and tested method.

[00:16:54]It was invented in the mid-1800s by people a lot cleverer than me. I'm new, John.

[00:17:02]It's still here.

[00:17:03]It's still working.

[00:17:05]And it is intended to The knowledge is passed through generations of people, and it's being carried on by these lads.

[00:17:14]Got to pay tribute to the new breed and also the old breed people.

[00:17:19]If you would have done this, they would have fitted the bars as well. They've done overhauls when the trains were running outside. They wouldn't have had the luxury of a block like we have this weekend.

[00:17:30]Um they would have gotten with it. It would have been hard, heavy work.

[00:17:36]Um yeah.

[00:17:39]So, you got to pay tribute to the system and the people that invented it and carried it on.

[00:17:44]For me personally, people like Ian Smith and John White who helped us. And me I personally, I can ring you at any time. He was a previous locking tester.

[00:17:54]And his mentor was John White. So, the knowledge gets passed on.

[00:17:59]Certainly, the next generation of locking fitters and maintainers and installers will still be around for a very long time. Hopefully, enjoying the job just as much as we are.

[00:18:08]We hope you enjoyed the video.

[00:18:10]And thank you very much to Network Rail and the locking teams for showing us around.

[00:18:14]Warren Donnelly.