https://i.redd.it/2xho42yfvnne1.jpeg
created by KinipelaH on 09/03/2025 at 12:53 UTC
348 upvotes, 18 top-level comments (showing 18)
Just having a wander along the canal and noticed this frame. Does anyone know what its purpose is? I don't think it's to stop the gate from opening the other way as the gates are too wide to do that anyway.
It's not really that important, we just couldn't figure out what it was for and I need to know 😅
Comment by My_useless_alt at 09/03/2025 at 12:56 UTC
407 upvotes, 4 direct replies
I'm guessing, but water is heavy, could it be that this lock just needed some extra reinforcement?
Comment by CautiousCapsLock at 09/03/2025 at 13:04 UTC
53 upvotes, 1 direct replies
Looking at the amount of grass in the far end of the lock doesn’t look used often, possibly to brace the back of the lock gates rather than full repair or replacement due to low usage?
Comment by Rookie_42 at 09/03/2025 at 13:02 UTC
20 upvotes, 1 direct replies
You say the gates are too wide, but what if you only move one at a time?
Is the lock actively used? I’m guessing they’ve had trouble with people deliberately leaving them flapping around, or possibly issues when flooded.
I’d say it’s clearly there to prevent the gates from going further than they should, so either due to fragility or that you could over-close them if doing them one at a time.
Comment by Clean_acc_ at 09/03/2025 at 13:02 UTC
22 upvotes, 0 direct replies
It’s a redundant lock gate so the brace behind it is to A keep it shut and B spread the load back.
Comment by -SaC at 09/03/2025 at 13:07 UTC
9 upvotes, 0 direct replies
It's a snowplough so that barges can be converted and clear the motorway if required.
Comment by Rowmyownboat at 09/03/2025 at 14:07 UTC
5 upvotes, 1 direct replies
To prevent from water or badly controlled canal traffic forcing the lock gates past their closed position.
Comment by RackOffMangle at 09/03/2025 at 13:36 UTC
3 upvotes, 0 direct replies
It is in fact to stop the gates folding back on themselves. It's a triangles structure, which are used to brace things as they spread load from one directional axis to another
Comment by Ascdren1 at 09/03/2025 at 13:15 UTC
2 upvotes, 0 direct replies
Strain relief. Takes a bit of pressure off the gate hinges when closed.
Comment by aerial_ruin at 09/03/2025 at 15:42 UTC
2 upvotes, 1 direct replies
Like people have said; it'll be for reinforcement. They might have had some issues with the gate at some point, and installed the a-frame to add strength. The only other option they would have r had, would have been to chose that lock off, including before the lock, so they could drain all the water around the gate on both sides. Then they'd go in and fix the issue, let whatever masonry work they'd need to do as well as any joinery repairs and cleaning the inlets for water.
Obviously a strengthening frame is a lot quicker to install than completely draining a lock and repairing, so they went for the quicker option. Might have been summer when they did it, so they might have needed to do the quicker fix. They'll have taken all the materials there by boat and made the frame there, rather than doing it in the workshop and transporting it, though they would have drilled any holes prior to taking materials to the lock.
Comment by royalfarris at 09/03/2025 at 16:33 UTC
2 upvotes, 1 direct replies
That support structure serves at least two purposes:
1. Gives extra support to the aging lock gates.
2. Makes it impossible to misalign the lock gates when you close them. Preventing situations where one gate is slightly more closed than the other and creating a dangerous possibility for the gates to wrap backwards when the chamber is filled.
Both of these, and especially 2) is important when you have selv service locks like these where the people operating them may never have done this before.
Comment by Sarahspangles at 09/03/2025 at 17:48 UTC
2 upvotes, 0 direct replies
The Canal and River Trust have a Facebook page and I think would answer questions.
We did a tour of a CRT workshop a few years ago. There‘s one in Yorkshire, one in the Black Country and I think maybe one in the South West or Wales. They’re only open once or twice a year. Would recommend. Every lock gate is unique although there are some basic design patterns. They’re replaced on a 25 year rolling programme, each one made to fit. The guys working on them look like Oompa Loompas building cathedral doors.
Comment by blackleydynamo at 10/03/2025 at 00:25 UTC
2 upvotes, 0 direct replies
Mooring posts look like the Rochdale? Pretty sure I've been through that lock, and I wondered the same.
My guess is that because it's a broad canal, and narrowboats will often only use one of the gates, it's to make sure that the two gates meet and seal properly at the top. So if a single gate is opened, the one that stays closed doesn't slip back at all.
It's unlikely to be needed to hold back the water; the gates are oak and typically weigh 1.8 tonnes each, and there's a cill under the water to keep them in the v-shape so when the lock is full the pressure keeps the gates closed. But if they're out of alignment at the top, the lock will leak and that section of canal will slowly lose water - which is a big problem on the Rochdale every year.
Comment by daedelion at 09/03/2025 at 13:03 UTC
3 upvotes, 0 direct replies
Canal engineers often have signature features they leave in the locks so people knew who designed them. This one's got the frame in to cleverly show their initial.
Comment by West_Yorkshire at 09/03/2025 at 14:18 UTC
1 upvotes, 1 direct replies
That canal looks familiar
Comment by Agent---4--7 at 09/03/2025 at 13:08 UTC
1 upvotes, 1 direct replies
Could be locked and sealed for good
Comment by Confudled_Contractor at 09/03/2025 at 13:26 UTC
0 upvotes, 0 direct replies
Points the way to the nearest pub.
Comment by Thick-Disk1545 at 09/03/2025 at 14:39 UTC
-3 upvotes, 0 direct replies
It’s a lock you open the gates to match the water level on the side you want to travel too
Comment by CptCockStrong at 09/03/2025 at 15:05 UTC
-2 upvotes, 0 direct replies
Sl no B in gk St )h
