Sunday, 17 October 2010

Oxford Canal Lift Bridges

The Oxford Canal lift bridges are notorious for being heavy and very user unfriendly. Previous attempts to help operators resulted in improper installation of rings in the floor to tie the chain to. Early results were that it was quite often difficult to chain a bridge open so when done rather than struggle to let them down again bridges were left up. Farmers were so pissed of at being on the wrong side of the bridge they soon got an angle grinder to chop off the rings. The bridges then went back to normal, heavy in the dry and very heavy in the wet.

In years gone by this would be corrected by the lengthsman (who we no longer have) they would adjust weight of the beam when the deck was wet. Another method I have heard of, though I cannot verify if this is true, was to have a sorbent filler in a box which would draw water in during the rain so adding weight to the beam balancing out the wet deck, is this true?

British Waterways have recently made a few changes to the Oxford Canal lift bridges to ease the problems that people have. They have now come up with what appears to be a good idea,  though still flawed. Bridges are weighted to the up position but are locked down. A BW key is required to open the bridge. Of course at £7 a time for the key no-one is about to leave a key behind so the problem of the farmers being stuck on the wrong of an open bridge now no longer exists. People still have trouble opening/closing the bridge but this is born about by them not being very mechanically minded. Standing on the bridge and trying to extract the key is not easy. The locking mechanism is as pictured below.DSCF8581You insert a key in the lock but it is difficult to operate from the front. The weight of the bridge is constantly on the lock it being always wanting to open. The weight has to be eased off the lock. This is achieved by pushing down on the handle while turning the key, not easy!DSCF8583But BW placed on the top of the lock a set of operating instructions. These make a handy seat. These instructions should read

First clear bridge of traffic (as if you need to be told)

Insert key

Push down on handle

Turn key to unlock

Allow the bridge to raise under control.

DSCF8582

But it doesn’t say this and even if it did it isn't so easy. So to operate the bridge follow these instructions.

1. Insert the key. (I assume you are not stupid and will not try lift the bridge with ‘traffic’ on it, if you are stupid get a canoe and you wont have to lift the bridge at all)

2. Place your bum on the instructions facing in the direction of the arrow.

3.  Put your head between your knees.

4. Turn key in clockwise direction whilst gently bouncing up and down on the ‘seat’. (Gentlemen: be careful, should you sense a searing pain and your eyes start watering investigate before proceeding)

5.  At this point you will feel like a right Wally, but the bridge will unlock.

6. Stand up when you feel the bridge rising to meet your better aspect and, holding on to the handle then the chain, allow the bridge to rise under control. (I will not tell you ‘DO NOT REMOVE THE KEY’ simply because it  can’t be done until the bridge is locked down again, the fact that BW tell you is an indication of what they think of boaters)

Closing the bridge is the reverse of opening.

1.Close the bridge using the chain and the handle. (Keep your feet out of the way of the descending lock)

2. Do a twirl cocking your leg over the lock and sit on the instructions facing in the direction of the arrow.

3. Gently raise and lower your toush on the ‘seat’ at the same time turning the key through 90o

4. With the head of the key in the vertical plane you can now remove the key.

However if you want to do it the BW way the instructions are above your head pointing upwards out of sight. Doh!

The only thing I don’t like about these locks is the chain. I think it should be chunkier. When this spindly little bog flush chain is wet I think one might have trouble gripping it.

To my certain knowledge (I have travelled the canal from Oxford to Banbury in the last month and seen for myself) these locks have been installed on Perry’s Bridge (234), Drinkwater’s Bridge (231)[see pics above] and  Chisnell Bridge (193) these are all between Oxford and Aynho.

If I recall correctly lift bridges north of  Aynho to Napton are all permanently up with the exception of Banbury which is a manual/hydraulic windlass operated bridge. [Please feel free to correct me if I am wrong]

South of Aynho Mill Bridge (205) is of aluminium construction and very easy to operate. Caravan Bridge (215) is permanently up.Shipton-on-Cherwell Bridge (219) used to be a balanced up bridge but this changed sometime ago, however a contact in BW said, back in the summer, this would revert in the near future (don’t hold your breath). Aubrey’s Bridge (221) is electro/hydraulic.DSCF5328a

Aubrey's Bridge 221

DSCF8576A34 Bridge 233 nice mooring  

The bridge under the A34 (233) has no name, that I know of, and as yet has no mechanisation/lock. It is a pig to raise, but one of the balance beams is soon to be changed so maybe it is due for a lock in the near future.

St Edwards Bridge (238) is locked up, but often the school uses it to access the fields. Being only an access bridge it is the schools responsibility to ensure that the bridge is up for boats to pass. There is a boat, seemingly permanent, on the bridge mooring on the south side of the bridge making it difficult to get off.

7 comments:

Brian and Diana on NB Harnser http://nbharnser.blogspot.com said...

Is it true they are going to electrify the Banbury lift bridge?

Maffi said...

Not that I have heard but that dont mean much. I will ask.

Seems a poinntles idea to me. It works fine as it is.

qsc85213 said...

IS VERY GOOD..............................

MortimerBones said...

I did the bridge at Aynho the other day and laughed at myself. I was reading the instructions and got as far as turning the key and the bridge raising and it took all the other instructions away with it!

Brad David said...

yo do yo wana follow ma blog san

Keith and Jo Lodge said...

Thank you Maffi for making me giggle ;0).
When we come your way I will let you know and you can come and work the bridges for me ha ha. Jo

Maffi said...

Brad I think I will pass on that. Boating is about chillin' out. Your blog list contains the word 'sport' far too often.