For those interested I have obtained some info on the two tunnels as well as Mile End Bridge. They responded as follows:
Attached are photos of the tunnels along with Mile End Road Bridge showing soffit levels at certain points. Controlling weir levels at these structures are:-
1. Maida Hill Tunnel = 29.73m Above Ordnance Datum (NOTE: Top of lock gates at Hampstead Road as no local weirs, normal water level is slightly lower).
2. Islington Tunnel = 20.97m AOD
3. Mile End Road = 9.26m AOD
Attached are photos of the tunnels and Bridge with indicators of height against profile. PLEASE NOTE THAT THESE ARE APPROX!
Bottom line was a clear message from the CR&T that they would not stop me but at my risk. So sense prevailed as being single handed loweringt he roof was not really an easy option. Shame really and with the weather this week I could have dropped the roof and left it off the whole way round.
Well C&RT rather unhelpful. Essentially they say have no idea about the tunnel sizes and I may proceed at my own risk. I have suggested they find out tunnel sizes and publish, they must have engineers drawings somewhere.
I received a rather unhelpful reply from the C&RT that merely referred me to their web site which I had already told them I had noted and that fails to provide any details on tunnel heights let alone profiles.
On Sat, 30 Mar 2013 09:59:32 +0000, "DBA Forum (WGBAI) - Murray
>Thanks Adrian that's helpful. My beam is also 3.8 (55 Piper) and max height is around 2.65 slightly less at wheelhouse edges as the roof slopes and a c. 2m width; I need to check.
>Dropping the pound level a foot or so would probably do me nicely and we are not exactly short of water this year!
Not a chance!
Maida Vale tunnel is on the pound that includes the entire Grand Union
Paddington Branch, and main line between Norwood top lock and Cowley
lock, and the entire Slough branch. How many billions of litres would
have to be drained to lower that significantly?
The first step in demounting the wheel house is to put the potted
plants downstairs .
Thanks Adrian that's helpful. My beam is also 3.8 (55 Piper) and max height is around 2.65 slightly less at wheelhouse edges as the roof slopes and a c. 2m width; I need to check.
Looks like I will need to remove the roof which is irritating as I can probably just about snuck under. I think a word with the Canals & Rivers Trust, as it now is I believe, is called for. Dropping the pound level a foot or so would probably do me nicely and we are not exactly short of water this year! I will post their response for the information of others.
On Fri, 29 Mar 2013 10:40:17 +0000, "DBA Forum (WGBAI) - Murray
>Can anyone tell me the maximum height on the ring? All I have been able to find is 2.79M at Mile End Bridge, which I can scrape under I think, but I also discovered a note suggesting 2.1M through Maida Vale tunnel.
The problem with Maida Vale and Islington tunnels is not their height,
which is quite generous and may well be 2.7 m, but their above-water
profile. Unlike most tunnels, they start sloping inward right at the
waterline. This means that for any vessel (such as mine) which has a
superstructure near the gunwale, the top edge of the superstructure
may be able to touch the tunnel wall. By "touch", I mean "scrape".
It takes almost superhuman steering skill not to touch at least once
during a transit. (The gauge beam of the canal is about 4.5 m, but I
think the tunnels are a little wider than that at the waterline; the
beam of my barge is 3.8 m)
My tactic is to tie small tires (very securely) all along both top
edges. This works, but is very time consuming. Also, it results in
rubbing a lot of crud off the tunnel wall, much of which falls on to
the barge roof.
Check with C&RT as to the actual headroom. And don't risk it if its
close to your air draft. A few years back, someone tried to take a
tjalk with a fixed wheel house through Islington, and got stuck in the
middle. BW lowered the pound, and towed it back out. When the BW
crew had gone, the barge skipper ran some water off the pound and
tried again. He got stuck again, a little further on than the first
time I believe. BW was not amused.
Can anyone tell me the maximum height on the ring? All I have been able to find is 2.79M at Mile End Bridge, which I can scrape under I think, but I also discovered a note suggesting 2.1M through Maida Vale tunnel.