Air draft on Thames/Oxford/GU ring

[MtB]

As the title... Is Osney bridge in Oxford the lowest bridge we'll need to go through when we do the Thames/Oxford/Grand Union ring later this month?

 

And which way is it best to go around? Presumably most traffic is going anticlockwise to go with the flow on the Thames section. Is there any merit in going the other way to avoid lock queues, or is the GU quiet enough anyway?

 

 

Cheers, Mike

[alan_fincher]

I can't think of any low bridges, (and we are quite a "tall" narrowboat).

 

Osney didn't strike me as tight at the river levels we saw - provided you go through the middle of the arch, (unlike some we encountered coming the other way, who were well jammed in at the edge).

 

The only other bridge I can think of is the one on the semi-tidal bit between Thames Lock, Brentford, and the gauging locks at Brentford. I gather that can be tight, but there was loads of headroom when we followed the usual advice about timings versus the tide on the Teddington to Brentford run.

 

Those like Blackrose or WJM who are Brentford based can probably confirm if it's ever a problem or not.

 

Clearly you can go faster if you come down the Thames, rather than up it. You must use significantly less fuel, and anybody who has a boat with little margin on the cooling is more likely to overheat if they go against the flow.

 

I can't see it will make much difference with the GU and Oxford locks, unless you have worked out that by going one way you will encounter more of the "busy" flights at the "peak" times, than by going the other.

[mrsmelly]

As the title... Is Osney bridge in Oxford the lowest bridge we'll need to go through when we do the Thames/Oxford/Grand Union ring later this month?

 

And which way is it best to go around? Presumably most traffic is going anticlockwise to go with the flow on the Thames section. Is there any merit in going the other way to avoid lock queues, or is the GU quiet enough anyway?

 

 

Cheers, Mike

 

Bridge 228 if I am correct on the Oxford is very low, I have been under it numerous times and I think its 228 its certainly one on that stretch of canal, Nightwatch do you concur or which one is it........

[NB Alnwick]

Bridge 228 if I am correct on the Oxford is very low, I have been under it numerous times and I think its 228 its certainly one on that stretch of canal, Nightwatch do you concur or which one is it........

 

There was a bridge near the railway station in Oxford, between the Thames at Osney and the southern end of the canal, that was so low that we had to take all the chimneys off - if that bridge is still there, it has got to be the lowest in the area.

[colin stone]

There was a bridge near the railway station in Oxford, between the Thames at Osney and the southern end of the canal, that was so low that we had to take all the chimneys off - if that bridge is still there, it has got to be the lowest in the area.

 

Osney Bridge at 2.3m - and I had to take a bit more off on my way up in Sep 05, including the wheel and replace with a car steering wheel:

 

Osney Bridge

 

Coming back down in Aug 08 was not so got. Thames had been Red the week before so both lever and stream was higher. Add in effect of lack on dredging and lock keeper dropped headwater by a few inches and we wnet aground under the bridge and were stuck for about an hour.

Edited July 7, 2009 by colin stone

[Dominic M]

A number of bridges on the Oxford Canal are lower than Osney (if the Thames is at normal summer level). Osney is never a problem for narrowboats, just the GRP gin palaces. If your stove chimney is on the starboard side then (heading north) the bridge at Aynho is tight as is the one further up at the lock above Aynho Weir.

[Chertsey]

A number of bridges on the Oxford Canal are lower than Osney (if the Thames is at normal summer level). Osney is never a problem for narrowboats, just the GRP gin palaces. If your stove chimney is on the starboard side then (heading north) the bridge at Aynho is tight as is the one further up at the lock above Aynho Weir.

Oh lordy, Osney was a problem for us, we have the dent in the roof to prove it. Wholly our own fault for not getting the chimney off in time, and not having a properly feeble chimney but a lump of cast pipe... But from that experience I would suggest that one way of looking at the direction in which to do the ring is that going upstream on the Thames is less hairy, especially if it rains.

[Dominic M]

Oh lordy, Osney was a problem for us, we have the dent in the roof to prove it. Wholly our own fault for not getting the chimney off in time, and not having a properly feeble chimney but a lump of cast pipe... But from that experience I would suggest that one way of looking at the direction in which to do the ring is that going upstream on the Thames is less hairy, especially if it rains.

Well that certainly couldn't have been what is described as "normal summer levels", but given climate change perhaps my terminology si now redundant.

 

"Get yer chimney off" should be the advice to all then

[alan_fincher]

Well we did it when it wasn't raining, and I've since learnt (via the forum) that the stretch from Osney bridge to the lock is one of the fastest flowing, (presumably due to the much restricted width before you reach the weir that bypasses the lock).

 

Our embarrasing moment came when we tried to moor in the one available space between bridge and lock and (twice ) ended up between bank and building opposite.

 

The boat we saw jam under Osney bridge whilst travelling upstream probably did so because it was going too slowly against the oncoming flow, and I'm sure I'd much rather tackle it first time downsteam than upstream.

 

Didn't occur to us to remove chimney, I think, and I can't recall an issue, so river was obviously lower for us.

 

I'm not sure Chalice would ever get from Brentford to Oxford if there was too much of a flow on, but I might be maligning her. We were well impressed with her performance going "downhill" though.

 

Different if you have a big engine, and big prop, no doubt, but although I enjoyed the Thames, I think I would get bored if doing it a lot slower - I'd still chose downstream if doing it again, just to speed the process, slightly.

[WJM]

Brentford High Street Bridge: At the very top of the tide there can be as little as four feet air draught! But give it about 20 minutes, time for a cup of tea, and you will have plenty of room, so dont worry. If you are approaching it on an incoming tide, dont do what I do and take a run at it, unless you are sure the back of your boat is lower than the front! BTW, I have a little flag on the forward part of my roof. It is marginally higher than all my roof clutter, so I use it like a cat's whisker, if it fits so will everything else!

[Chertsey]

Well that certainly couldn't have been what is described as "normal summer levels", but given climate change perhaps my terminology si now redundant.

 

"Get yer chimney off" should be the advice to all then

It was last August; I think it had just come off yellow boards. We went from Oxford up to Lechlade (it was definitely on yellow for most of that) and then back down to Brentford. Down was definitely harder work and more stressful.

 

Well we did it when it wasn't raining, and I've since learnt (via the forum) that the stretch from Osney bridge to the lock is one of the fastest flowing, (presumably due to the much restricted width before you reach the weir that bypasses the lock).

 

Our embarrasing moment came when we tried to moor in the one available space between bridge and lock and (twice ) ended up between bank and building opposite.

 

The boat we saw jam under Osney bridge whilst travelling upstream probably did so because it was going too slowly against the oncoming flow, and I'm sure I'd much rather tackle it first time downsteam than upstream.

 

Didn't occur to us to remove chimney, I think, and I can't recall an issue, so river was obviously lower for us.

 

I'm not sure Chalice would ever get from Brentford to Oxford if there was too much of a flow on, but I might be maligning her. We were well impressed with her performance going "downhill" though.

 

Different if you have a big engine, and big prop, no doubt, but although I enjoyed the Thames, I think I would get bored if doing it a lot slower - I'd still chose downstream if doing it again, just to speed the process, slightly.

 

If you don't have the power to comfortable tackle it upstream, is it safe to attempt to go downstream? Not personal to you Alan, a more general query.

 

We went of from our encounter with Osney Bridge to get the fore end jammed under the walkway of the bottom gate of Osney Lock. Fortunately there was a very large gentleman strolling on the lockside, and we got him to stand on it for us.

 

After these traumatic events we made our way to Abingdon where Maffi, Bones (and PJ?) ministered to us with fine claret.

Edited July 8, 2009 by WarriorWoman

[alan_fincher]

It was last August; I think it had just come off yellow boards. We went from Oxford up to Lechlade (it was definitely on yellow for most of that) and then back down to Brentford. Down was definitely harder work and more stressful.

When we did the Thames ring at Easter, which was quite benign, some 30% to 50% of locks seemed to be displaying yellow boards.

 

It appeared to be quite random which, and certainly had little relevance to any difficulty of navigation.

 

I was just told they can be displayed, even if the water is only rising very marginally ? Is that correct, or was I being bull-shi**ed ? If true, they seem fairly pointless ?

[WJM]

You sure they were not the 'No Lock-keeper' Yellow boards?!

[alan_fincher]

You sure they were not the 'No Lock-keeper' Yellow boards?!

No! - I'm probably talking out of my backside - the Thames isn't really something I claim to understand.

 

I'm thinking of large discs, maybe nearly a foot in diameter, attached to the lock gates or besides the locks, which have a hinge down the middle, allowing semi-circular panels to be swung. A lot of the locks had this done to display a large yellow disc.

 

Example here......

 

 

We passed through far more locks that had this, (well into double figures), than ones that were boater operated because it was the lockies lunch time, (absolute maximum of 4).

 

Please enlighten me about what those discs should mean, and, (if not river conditions), where would river conditions be displayed, and how, please ?

Edited July 8, 2009 by alan_fincher

[WJM]

LOL :-)

 

 

The yellow disk means the lock-keeper is not there but the power is still on so you can work the lock yourself!

 

Well it either means that or the lock-keeper is there but he forgot to fold the sign up again when he got back from lunch!

 

 

The Stream Warning signs are usually tied to the top of the gates and are rectangular and have the warning written on them.

Edited July 8, 2009 by WJM

[KenK]

LOL :-)

 

 

The yellow disk means the lock-keeper is not there but the power is still on so you can work the lock yourself!

 

Well it either means that or the lock-keeper is there but he forgot to fold the sign up again when he got back from lunch!

 

 

The Stream Warning signs are usually tied to the top of the gates and are rectangular and have the warning written on them.

 

According to the latest mag from the EA they are going to change the colour to blue as the existing sign causes confusion.

 

Ken

[alan_fincher]

Well it either means that or the lock-keeper is there but he forgot to fold the sign up again when he got back from lunch!

Well I said, I didn't know, (and said "seemed to be displaying yellow boards" in my post, because there seemed to be no match with river conditions).

 

Bonkers !

 

We saw this repeatedly, and 90% of the time the lockie was working the lock, (as he had just done at the one pictured!).

 

Completely pointless, then it seems !

 

I agree something other than yellow would seem a more appropriate way of saying "lockie absent, (but probably not!)".