Does size matter?
If you want to cruise the whole system, then yes. But DON'T believe the myth about a 57ft narrowboat being the maximum size. I don't know who started that idea, but it surfaced sometime in the late 1980s. It is NOT TRUE!
If you want to be pedantic, deep in East Anglia on the fenland edge there is a lock on the Little Ouse river stated as being 40ft in length, which permits navigation to the Norfolk town of Brandon and further upstream for the adventurous. Neil Arlidge of that maverick bunch, the Tuesday Night Club estimates a 48ft narrowboat could probably get through on the skew however. Otherwise, I know a 58ft 6in boat will go everywhere, because I did it. Others have told me that the two navigations with the most restricted length on the connected system, the Calder and Hebble and the Ripon Canal, can be passed with a 60ft boat, although it involves removing fenders and doing a couple of locks on the C&H backwards. Also, a 62ft boat will be able to navigate almost all of the entire connected waterway network, the Calder & Hebble and the Ripon Canal being the "no go" areas (plus a few isolated waterways). And a 70ft boat can happily cruise from, say Liverpool or Manchester to London or Bristol.
Amended 28/10/08 (thank you to "Hairy Neil" from Canalworld.net) for pointing out my error!
Only those coloured green are connected to the main system of waterways.
| Dimensions of Navigations with locks less than 70ft | ft | in | ft | in |
|---|---|---|---|---|
| River Ancholme (to Harlam Hill lock) | 68 | 0 | 19 | 0 |
| River Ancholme (Harlam Hill Lock and above) | 40 | 0 | 12 | 0 |
| Bridgewater & Taunton Canal | 54 | 0 | 13 | 0 |
| Calder & Hebble Navigation | 57 | 6 | 14 | 1 |
| Chelmer & Blackwater Navigation | 60 | 0 | 16 | 0 |
| River Derwent & Pocklington Canal | 55 | 0 | 14 | 0 |
| Forth & Clyde Canal | 68 | 6 | 19 | 8 |
| Huddersfield Broad Canal | 58 | 0 | 14 | 2 |
| Leeds & Liverpool (Leeds to Wigan) | 62 | 0 | 14 | 3 |
| Leeds & Liverpool (Rufford Branch) | 62 | 0 | 14 | 3 |
| Little Ouse River (aka Brandon Creek)* | 40 | 4 | 12 | 0 |
| River Medway | 65 | 0 | 15 | 6 |
| Middle Level - Forty Foot River through Welches Dam lock** | 47 | 0 | 11 | 0 |
| Monmouthshire and Brecknockshire Canal*** | 64 | 9 | 9 | 2 |
| Neath Canal | 60 | 0 | 9 | 0 |
| River Parrett | 54 | 0 | 14 | 0 |
| Ripon Canal and River Ure | 58 | 0 | 14 | 6 |
| River Rother | 56 | 0 | 13 | 9 |
| River Welland | 62 | 4 | 27 | 10 |
| Sheffield & South Yorkshire Navigation | 61 | 6 | 15 | 3 |
| Stainforth & Keadby Canal | 65 | 0 | 17 | 0 |
| Swansea Canal | 69 | 0 | 7 | 6 |
* This restriction only applies to the last mile of the navigation - otherwise it is unrestricted
** This is a seldom used route. My understanding is that Welches dam is currectly out of use again. The main route will take a 70ft boat - although at Salters Lode - the connection with the tidal Ouse - a craft longer than 62ft has to wait until the right state of tide to pass through
*** Improvements to The Head of the Valleys Road at Gilwern led to the canal channel being altered and created a sharp right angle bend which restricted the maximum length to 50ft. However, the road has recently been reconstructed and the canal straightened out once more. BW currently state 55ft as the maximum, but the original barges were 64ft 9in and the locks have not been altered. Worth investigating if you want to put a longer boat there.