This route attempts to follow the course of the 1779 canal route closely. The only deviation is in the area around the A38 where a slight movement to the south avoids an unnecessary crossing of the A419.
The start of this route from Whitminster Lock is the same as the other two. At the site of Lockham Aqueduct, this route leaves the river and follows the 1779 canal route to the A38 roundabout as described in the M5 Bridge Shared Route .
At the A38, the canal passes under the each side of the roundabout in separate new bridges as before and is then lifted in a new lock by about 1.5m-2.7m to a level suitable for passing under the M5. If the M5 levels permit, the whole original 8ft 9ins rise might be accommodated and the construction of a second new lock east of the M5 avoided. Alternatively, the whole level differences could be accommodated by the new lock just east of the M5 but this would result in extra excavation between the A38 and M5.
The original canal bed between the A38 and Westfield Lock has been obliterated and a new channel will have to be constructed on or close to the 1779 line. This will sever the farm land between the A419 and the River Frome so one or more accommodation bridges may be required unless the A38 bridge, or an extention to it, is used.
There is a cattle crossing more or less on the line of the canal
passing under the M5 (pictures) . The use of
this structure would be difficult and expensive. The main problems are
Such a new bridge would be a major undertaking as its alignment in
under the junction 13 slip roads as well as the M5 itself.
The number of lanes and hard shoulders to be crossed is 14 in all!
The cost of the structure, although large, is unlikely to be the only expensive factor. The cost of lane rental for the works and the likelihood that various slip roads on and off of junction 13 will have to be closed for significant periods means that a very heavy surcharge could be levied by the Highways Agency. W.S.Atkins have estimated that these costs might be of the order of £1m-£1.5m for a 4 week contraflow based on 1991 traffic levels. More recent estimates indicate the cost to be around £3m.
The bridge will probably have to be about 9m wide to take the canal, its towpath and the farmers' cattle under the M5. The relocation of the new bridge slightly to the south in order to preserve the existing cattle culvert might be worth considering.
Having passed under the M5, the new canal channel would pass through the second lock should this be necessary.
The new channel would follow the course of the original 1779 route and, again, would sever the farm land between the A419 and the River Frome. Although this would be bridged by Westfield Bridge at the east end, this humpback bridge is unlikely to suffice as the sole access to the land and a further accommodation bridge is likely to be needed.
One of the main problems with this, and the shared M5 bridge option, is that the owners of the land involved may not be happy about the way their land would be severed into a number of smaller pieces by the restored navigation.