Determining dimensions for restoration


To determine the correct dimensions for a boat for the purposes of restoration you first have to make a number of templates using plywood sheet, on which you record the required dimensions using a pencil.


If the boat is considerably deformed and sagged you start with the mast frame, also known as the master rib (image 2), for determining the original dimensions. This is the widest point of the boat; all lines run around this. The mast frame is also the strongest part of the boat because it has to be able to take all of the forces from the mast. Using a template plank you measure at the mast frame whether the boat is still symmetrical at that point on the starboard side and on the port side. If it is you know that you still have the original dimension for that point. If that is not the case and you measure a difference you have to look at what is wrong and what can be deformed.

From the mast frame you proceed towards the stern, to the forward bulkhead of the afterdeck. In Zeeland that is called the beunschot (stowage hold bulkhead). The ‘beun’ (stowage hold) is the space under the afterdeck that you use for storing ropes and nets. You also use a template for the stowage hold bulkhead. At the locations where the boat’s skin has warped considerably you use a template in order to determine the correct dimensions (image 4).

You can easily make a template from a number of pieces of plywood that you connect together using planks to give them rigidity (image 3). You can write down the required dimensions onto the plywood (image 1) and/or stick small pieces of plywood onto the larger sheets in order to indicate the correct dimensions.

The number of templates you make depends on the type of vessel and the condition of the vessel. For a seriously deformed vessel you make six, seven or even more templates, which will in any event include templates at the positions of:

  • the mast frame, widest point of the vessel
  • the bollard frame, where the skin bulges out considerably
  • the front of the afterdeck (stowage hold bulkhead)
  • the back of the afterdeck
  • potentially an additional template for the angle of the bilge

Mark the following dimensions onto the templates:

  • width of the bottom
  • width and height of the inside of the rubbing strake
  • width and height of the top of the sheer strake
  • the position of the overlap of the skin planks (you do this for indicative purposes because once the old parts have been demolished you will lose these dimensions).

If the bilge is still in good condition and has its original width you can rebuild such a vessel fairly quickly. If that is not the case you will have to construct a new bilge and in reality, therefore, a completely new vessel.

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Tools Required

  • Folding rule
  • Pencil
  • Glue
  • Screws

Materials Required

  • Planks
  • Plywood sheets
  • Small pieces of plywood (potentially)