Grand Union air draught

[Bronco99]

Please, please help if you have direct experience with this rather than, like me, loads of reading up, official and unofficial specs and guidelines and tips on revving with bins full of water! 

I want to get up the Grand Union main line from Bulls Bridge as close to the Warwick Cape locks as possible. I know what the CRT specs say and I know how they differ to other publications and chatter in pubs etc. 

I have a height of 7" (wheelhouse off, square cockpit screens). Lets assume a chart datum water level and take into account my 9" beam for the arched bridges.

Does anyone have any actual experience of attempting this passage with a similar air draught. 

If it really isn't possible then how far north IS it possible to get?

Really appreciate some first hand knowledge of this, recent if possible but all welcome.

Cheers all.

[matty40s]

Unless you can remove your cockpit windows, Stockton is about as far as you can go.

[ditchcrawler]

Are you a wide beam and booking the tunnels, as if not you could  be in trouble if you meet something and have to pull against the wall

[Allan(nb Albert)]

Delta Marine Services at Nelson Wharf, Warwick build widebeams and barges which are usually taken down the GU. Ask to speak to Gary Ward.

[Bronco99]

30 minutes ago, matty40s said:

Unless you can remove your cockpit windows, Stockton is about as far as you can go.

Can I ask why you say Stockton? Is it from experience? the CRT specs you show are dubious to say the least, they equate 2.34m to 3ft 4!at one point! You can look in more detail at the official guidelines (see below) but it's more folks who've gone up with a 7" air draught I'd like to know about. 

[matty40s]

46 minutes ago, Bronco99 said:

 

I have a height of 7" (wheelhouse off, square cockpit screens). Lets assume a chart datum water level and take into account my 9" beam for the arched bridges.

 

 

 

28 minutes ago, ditchcrawler said:

Are you a wide beam and booking the tunnels, as if not you could  be in trouble if you meet something and have to pull against the wall

 

[matty40s]

3 minutes ago, Bronco99 said:

Can I ask why you say Stockton? Is it from experience? the CRT specs you show are dubious to say the least, they equate 2.34m to 3ft 4!at one point! You can look in more detail at the official guidelines (see below) but it's more folks who've gone up with a 7" air draught I'd like to know about. 

The Blue Lias bridge, and others will probably stop you. Although it lists 7' 11" as headroom, that is likely to be at the centre of the arched bridge....the towpath takes up some of one side, and in this particular bridge, also has protective rubber buffers, which push boats over to the other side even more.

Your windows do not appear to be particularly angled in from the side(tumblehome), and I think you might struggle without removing them.

[Bronco99]

Thanks for the link Matty. I'm still hoping professional services won't be necessary to get me where I'd like to go. Free advice is always welcome of course, hence my post ?

 

Having said that, I'll want a trailer tow from Warwick to the Stratford Avon.

[TheBiscuits]

1 minute ago, Bronco99 said:

Having said that, I'll want a trailer tow from Warwick to the Stratford Avon.

 

Is this a gradual journey while exploring or do you think cruising to Warwick will make the next part of a delivery trip cheaper?

 

If you are simply trying to get to the Avon or the Severn then just stick it on a trailer close to where it is now and deliver it by road near where you want it going.  If you want to explore and play out on it, that's different of course.

[matty40s]

The cost of a trailer will not be much different from Stockton, Calcutt, Stowe Hill or somewhere else so I would work out how far you can actually go and arrange it from there.

[Alan de Enfield]

1 hour ago, Bronco99 said:

I have a height of 7" (wheelhouse off, square cockpit screens). Lets assume a chart datum water level and take into account my 9" beam for the arched bridges.

Are you sure of those dimensions ?

[matty40s]

On the subject of the previously mentioned experts, Delta Marine. They had a widebeam Dutch barge stuck the other side of Blue Lias below the concrete bridge at Warwicks Fly Boats last year for weeks, until CRT managed to remove some underwater concrete from it, and the rubber bits from Blue Lias as well. It was less than 7ft headroom.

21 minutes ago, Bronco99 said:

the CRT specs you show are dubious to say the least, they equate 2.34m to 3ft 4!at one point...

 

Well he seems to be able to spit mistooks?

[Bronco99]

3 minutes ago, matty40s said:

The Blue Lias bridge, and others will probably stop you. Although it lists 7' 11" as headroom, that is likely to be at the centre of the arched bridge....the towpath takes up some of one side, and in this particular bridge, also has protective rubber buffers, which push boats over to the other side even more.

Your windows do not appear to be particularly angled in from the side(tumblehome), and I think you might struggle without removing them.

Thats interesting. My understanding was always that not only were the official specs conservative, but that they were set out with most types of vessel in mind, including wide beams (which mine is only partial) and various cockpit types. I can only try!!

 

I have a small cruiser at Rickmansworth atm heading to Ashwood Marina so just scouting the lay out but just bought this bigger boat too so I'm going to make a cruising ground of Evesham (where she is and I'm from) down the Severn Estuary into Bristol to Bath (where I live), up the K & A which I've done a few times into London and up the GU and then (hopefully) a short tow down the A46 from Warwick back on the Avon at Stratford. But you're right, the towing distance itself doesn't make a huge difference to the trailer cost. I don't know where a decent slipway is yet!!

[Victor Vectis]

38 minutes ago, Allan(nb Albert) said:

Delta Marine Services at Nelson Wharf, Warwick build widebeams and barges which are usually taken down the GU. Ask to speak to Gary Ward.

Yes.

And cause all sorts of trouble in doing so.

 

 

ETA As per Matty's post #12

Edited January 5, 2021 by Victor Vectis

[Sea Dog]

1 hour ago, matty40s said:

Unless you can remove your cockpit windows, Stockton is about as far as you can go.

There's some dodgy metric to imperial maths going on in that table Matty!

[Rob-M]

5 minutes ago, Bronco99 said:

Thats interesting. My understanding was always that not only were the official specs conservative, but that they were set out with most types of vessel in mind, including wide beams (which mine is only partial) and various cockpit types. I can only try!!

 

I have a small cruiser at Rickmansworth atm heading to Ashwood Marina so just scouting the lay out but just bought this bigger boat too so I'm going to make a cruising ground of Evesham (where she is and I'm from) down the Severn Estuary into Bristol to Bath (where I live), up the K & A which I've done a few times into London and up the GU and then (hopefully) a short tow down the A46 from Warwick back on the Avon at Stratford. But you're right, the towing distance itself doesn't make a huge difference to the trailer cost. I don't know where a decent slipway is yet!!

The GU was built for narrow boats, a pair can travel lots of it breasted up but they would be much lower than you especially when they are fully loaded.  The arch of the bridge is where you will struggle with headroom.

[Bronco99]

18 minutes ago, Alan de Enfield said:

Are you sure of those dimensions ?

Ah, I see you refer to my inaccurate and slightly dyslexic unit of length symbolism, dear fellow! 

I must admit you had me wondering which marine asylum you'd escaped from with your prose regarding cannibals, machetes and wastelands ?

 

Perhaps a Dayskipper refresher course is in order for me, hey... 

[GUMPY]

6ft6 over 8ft width will easily get to Stoke Bruene. Been there done that on Parglena (61x11'6) with the wheelhose down. None of the bridges were even remotely tight with one exception, the bridge between locks 58 and 59 is on a slight bend and was always tight because of the overall size of Parglena.

[Alan de Enfield]

24 minutes ago, Bronco99 said:

Thats interesting. My understanding was always that not only were the official specs conservative, but that they were set out with most types of vessel in mind, including wide beams (which mine is only partial) and various cockpit types. I can only try!!

Remember that the dimensions quted are the maximum and will not relate to any boat with more than one of those dimensions ( so a 'high' boat, cannot have the same beam as a 'low' boat)

 

You will not get a wide beam boat and a narrowboat that are both at the maximum height thru the same bridge.

 

Quick example worth a 1000 words.

 

 

[Bronco99]

8 minutes ago, Alan de Enfield said:

Remember that the dimensions quted are the maximum and will not relate to any boat with more than one of those dimensions ( so a 'high' boat, cannot have the same beam as a 'low' boat)

 

You will not get a wide beam boat and a narrowboat that are both at the maximum height thru the same bridge.

 

Quick example worth a 1000 words.

 

 

That is a good example, Alan, and I've seen it on this forum before. Trouble is this infernal boat of mine, at 9ft comes somewhere between wide and narrow, so makes it difficult to judge or follow guidelines whether it would get through some of these bridges, whereas it would be an easy decision on a full widebeam of say 12-13ft. Bearing in mind the minimum CRT "conservative" headroom is 7'4 and I'm 7'.

Edited January 5, 2021 by Bronco99

[Keeping Up]

If you do set off on this trip, some useful info may come from knowing that the tightest arch below Braunston is probably the white one at Apsley (I got stuck there once on a Dutch Barge and had to hacksaw the stern rail off to get through) and the lowest flat bridge below Braunston is possibly at Northchurch (we had to flood the bilges there). Further north, as said here, the arch of the bridge by the Blue Lias at Stockton is about as difficult as they get, but by staying close to the towpath you just might get through. If you don't, you'd have to reverse back up the flight! Not sure which is the lowest flat bridge in the northern section, possibly just beyond Stockton WFB, below the lock where the above-mentioned one from Delta Marine got stuck (I once got stuck there trying to take a breasted pair through, it's so nearly 14ft wide that we got nearly halfway through before getting so well wedged that we had to borrow a tirfor from WFB to pull us back out)

[Bronco99]

This is all good stuff. I'd hate to have to follow my head instead of my heart but it does seem from the information I'm getting that I might struggle on the GU. I'm aware that these wide beam cruisers are designed for river/coastal work but I know the K&A can accommodate, despite the low bridge at Newbury.  Perhaps I'll save up for some foldable screens, or just go as far as possible without taking any silly risks.

 

Funny how there are lots of maps available for wide beam waterways, of which GU is one, but they never factor in beam/headroom together. Something that, with all these arched bridges and increasing widebeam cruisers looking to explore those waterways, I'd have thought might be starting to be compiled. 

 

Anyone else with any practical experience of this please shout out.....

[john6767]

The bridge at the Blue Lias at Stockton (Stockton Lane Bridge 23) is, low, on the skew, very rounded, not that wide, and the towpath sticks out quite a bit.  You have to be very careful with a narrowboat, and there are plenty of chunks out it from people who were not careful!

 

Not the best photo, from canalplan

[john6767]

This is a photo from the other direction, shows the skew and towpath protrusion

 

[Bronco99]

Don't think I'd get under that in my boat ?