The MARYANN W

POP'S STEAM BOX

This post will tell everything my Pop (and I) know about a steam box and it's applications in wood boat construction. A steam box is used to bend wood ribs to the correct shape to form the framework of a boat, then also used to bend the planking. I don't know all the technical terms and never will. This is my story of a man with a grade eight education educating himself!

Pop learned to use a steam box from William Griffith (his father-in-law to be). Mr. Griffith loaned Pop the use of his boatshed, steambox and clamps in the late 1930's to build a dinghy (copied from friend, Ben Coates's, dinghy). Perhaps he was "wooing" a suitable suitor for his daughter.

Wm. Griffith was experienced in boat building and was able to give input when needed - or help. He taught Pop to "spile out" a template or pattern made of thin (1/4 inch) wood - in the shape required.

The dictionary definition is: "Spiling: in shipbuilding, the dimensions taken from a straight line, a molds edge, or rule-staff, to any given "sny" or curve of a planks edge." "Sny" is defined as "a gentle bend in timber, curving upwards: when it curves downwards, it is said to hang." Ribs would be "Sny" which means they curve up from the keel.

They used dividers to measure and mark the curves required for the rib on the "spiling board". The pattern would then be transferred to the rib in order to cut it to the correct shape to fit once it was bent.

They steamed the oak rib 30 - 40 minutes or so, then clamped it in place at the keel, bent it while it was still very hot and very damp, to the desired shape, and clamped the other end into place. Oak was used for ribs as it stayed pliable for 10 minutes or so. The clamps were not put directly onto the planking to hold it in place - blocks of wood between were required as the clamp would bruise or dimple the lumber.

Pop learned the basics from Mr. Griffith then built a steam box in his own boat shed in the 1940's to use in building the "Maryann W", his 43 foot commercial troller.

The steam box was built of 1 1/2 to 2 inch thick clear hemlock, without knots, to withstand intense heat and steam. The box was very long to accomodate long pieces of lumber, but tall and thin. The dimensions of Pop's was about 4 to 6 inches wide, 14 inches tall and 20 feet long. The box was solid with a door on one end - it was as airtight as possible to keep the steam inside.

The box was up off the ground, about belly level, inside the boat shed with a 2 inch iron pipe attached under the center to a hole in the box to let steam in. The pipe went straight down from the box then had an elbow to right angle it. It ran through the wall of the boatshed to the top of a 20 gallon drum which was laid on it's side on a metal framework directly over a wood fire (a good distance from the boatshed). A filler hole was in the opposite end of the drum to add water. The drum needed refilling often as the water steamed away quickly over a hot fire. Pop said the setup was crude but it worked.

He and boatbuilder Alec North "spiled out" many, many patterns for ribs of the "Maryann W". Pop said it took large C-clamps and a great deal of brute strength to bend and clamp the ribs in place for the 43 foot troller. They worked 30 days to lay the keel and put all the ribs in place.

This all sounds logical and simple enough - but I believe it was difficult - judging by the language I learned while watching Pop bend a board or two in the 1950's.