This article apparently gravitated from our previous website. We think Steve Kelly wrote it and perhaps one day we should seek him out and confirm it!
Steve Kelly has been involved with wooden narrow boats for many years. As a founder member of Ashton Canal Carriers, he helped to rebuild Maria, in 1978, and played a large part in her refit in 2004. He built his own steel boat, Clio, which operates as a working tug. He is in demand in the wooden boat community for his woodworking skills.
Boatbuilding by Steve Kelly
Wooden boats are actually held together by ironwork, though this rarely needs as much attention as the woodwork. The design has evolved over time into the form we know today as the norm.
Laying the bottoms
Usually a narrow boat has an elm bottom, made up of 3″ by 7′ planks. Their width depends on the tree they came from, but wider is better and a builder will ask for planks to be sawn as wide as possible. On Maria, they average around 18″.
The bottoms are laid across the boat and fixed to the Keelson (aka Kelson), by spikes. Spikes are basically large iron or steel nails. A 14″ spike is quite common. The keelson is a beam of about 11″ by 5″, made from long sections, running the length of the boat (around 70 feet), that acts as the spine.
Fixed to the bottoms are the iron knees which support the 2″ thick oak side planks. The side planks are also fixed by spikes through the bottom boards. This calls for accurate drilling up through the bottom boards and a lot of spikes being driven up through the first, or garboard, plank.
The long spikes come through the top edge of the plank and in older boats these would often have been riveted over washers (aka roves).
In more recently built boats they are often clenched over and, for repairs, shorter spikes are used, that do not come through at all.
A side plank is around 9″ wide, but wider where is approaches the stem or stern posts to
allow for the graceful sweep.
The number of rows of planks depends on the design. For Maria it’s five, but for Elton and Southam, a pair of Big Rickies, it’s six.
The bow and stern of the boat call for shaped stem and stern posts, rebated to take the side planks, and shaped timber knees to accommodate the curves.
These posts are mainly fixed by being spiked to the side planks, though an iron or timber knee is fixed between stempost and kelson.
As stem and stern posts are large and heavy, and the side planks they attach to usually need to be steamed, fitting them is a tricky task. Bends are needed at each end of the hull, and oak does not bend easily, so steaming is needed.
First the plank is carefully shaped, there will be very little time to make changes when fitting.
The plank is steamed in a steam chest for several hours. A good steam chest can be made by cutting the ends out of 45 gallon oil drums and welding them together to form a tube. The steam is not under pressure; it is simply hot and wet.
After a few hours, an oak plank is remarkably flexible, but also remarkably hot, remarkably heavy and remarkably awkward to carry around a boatyard, with a remarkably large number of items left in the way.
If all goes well, the plank is positioned and fixed with spikes and bolts, whilst still hot.
The remaining side planks are bolted to the knees, the scarf joints being staggered throughout the length of the boat.
Inside the boat, shearing of ½” oak is fixed vertically on a bedding of hot chalico, tar and canvas, or building paper. This stops the caulking and any dampness, coming through. Caulking from the outside follows, to make all the seams between planks watertight. Traditional chalico is a hot mixture of pitch, tar and horse manure (to give it body).
To give added strength, a lining board or counter strake , similar to an inwale on seagoing boats, is fixed inside the topmost side plank. To this are fixed the supporting blocks for the cross planks and fixings for cross chains, this also gives support to the gunwales capping off the hull usually around 5″ by 2″ thick. This lining board does not extend into the cabin space except in motor boats to assist in supporting the counter stern. The cross planks and chains stop the long hull from spreading or bowing inwards.
At the fore end, additional timbers are fixed inside the top most bends to give strength and support to the deck beams. Across the foremost part immediately behind the stempost top are fixed breast timbers running across the boat, to better secure the top bends and the T stud.
Cabin work and decks all need to be built on the hull, and protective ironwork fitted. Before this, the final shaping of the hull and stem and stern posts is carried out. Ice plating, thin iron sheets are fixed at the fore end, and sometimes along the loaded waterline though this is rarely seen, and protected by the heavier iron rubbing strakes.
Motor boats differ in that a shorter sternpost is fitted, and after laying the longitudinal counter bottom, or uxter, boards a counter block is fixed. This is effectively a very short but wide sternpost to which the counter side planks are fixed.
One of the last items to fit is the floor, normally known as the shutts, these are removable sections each side of and at the same height as the keelson. Maria’s floor is not quite like that, having simple floorboards raised above the elm bottoms on blocks.
Tools and equipment used in the canal era would probably have been recognisable to Drake’s shipbuilders. Today, many power tools can be used for shaping and cutting timbers. Materials used can also be modernised, as many imported hardwoods are now much more economical than English oak and elm, and fixings can be galvanised for durability. Unfortunately, coal based tar products are now more difficult to obtain, but are to be preferred to oil based substitutes.
Few complicated joints or techniques are required beyond the setting out and shaping, or spilling of curved members, and whilst still being a fairly labour intensive operation, these traditional craft have been production engineered to a large extent. This is particularly true of the short haul Birmingham day boats which were almost mass produced,and the larger concerns, less true of the products of the smaller builders such as Lees & Atkins.