The challenges to building a canal

[Heartland]

Within this context all navigations often found problems to overcome when they started to make a new waterway, but some had more difficult challenges than others. In this context the Worcester and Birmingham Canal encountered many issues, Firstly with getting their act, then building a barge width waterway from Birmingham. The problem of water supply was another challenge as was the task of getting a lock in the 7ft wide bar that separated it from the Birmingham Canal Navigations. Trade was affected and their first links with another canal was the Dudley Canal at Selly Oak and the Stratford upon Avon Canal at Kings Norton. As with other waterways the transport of coal was important and yet that main supply came via the Dudley initially when the Dudley was completed yet it was an imperfect supply as the problems with Lapal Tunnel led disruption of trade there. 

 

The Worcester & Birmingham built some high embankments and long tunnels to reach the point where the levels fell away and the barge locks as intended were replaced in a new scheme to build boat lifts. That experiment also was suspended and narrow locks made instead. Additional acts were needed to raise funds and the canal was not completed to the Severn at Diglis until 1815 during a period when the UK were at war with France and the various economic consequences of that war that hindered finance.

[Pluto]

Coal may have been the incentive to build midland canals, but it was not so further north, where limestone was considered as the primary traffic during early planning and construction. The demand for coal in the north was a result of the success of canals in opening up the economy, rather than the most important initial factor.

 

Embankments are of particular interest to me at the moment, as they could be seen as Britain's major contribution to early canal engineering. Brindley certainly used them on the Bridgwater, though I suspect the problems he had led his later canals to be more of the contour following type. Soil mechanics was little understood at the time, though French and German engineers were studying the subject in much more detail than those in Britain, reflecting their higher level of mathematical understanding on the European mainland. English universities did not start teaching calculus until the 1830s or so, at least forty years after the French. However, soil mechanics was never really sorted out until the 20th century, when mathematical analysis had advance far enough to solve the problems. Embankments had been built prior to canals, particularly for flood prevention, but their use on canals required them to be load bearing, which created greater difficulty in construction and maintenance. 

[Heartland]

One of the biggest challenges for the Worcester and Birmingham was to have a lock across the bar so that craft could pass between the two waterways. They had been asking for it about the time the Stratford reached Lapworth and a through carrier's route from the Warwick & Birmingham had become possible. There was a provision in the BCN Bill of 1806, but that provision became a separate bill and that second bill application faltered in parliament. There was a certain irony in that their application to parliament before the bill progressed urged for parliament to consider the problem of their existing coal supply from Netherton through the Lapal Tunnel was frequently disrupted.