STEEL SPECIFICATION

Steel is be far and away the commonest material used in the construction of narrow boats. A classification system using a series of numbers and letters is used to differentiate different types of steel used on narrowboats.

Narrowboat hull construction. Steel is the most common material used on narrow boat hulls

Narrowboat steel hulls have a unique classification to differentiate between the types of steel used.

Steel Specification… What Does It Mean?

Standard steel certification is currently to EN 10025

A classification system using a series of numbers and letters is used to differentiate different types of steel used to construct a narrowboat hull. If you are contemplating building a shell, speak to your local steel stockholder.

But what do the letters and numbers mean?

A common steel maybe classified under EN 10025 as being S 275JR

This is uncoded as:
S – Structural Steel
275 – A minimum yield strength (Reh) which measures stress loads as the material transitions from plastic to elastic
JR – relates to figures obtained from a Charpy v notch impact test

And that is why it is probably better left to your chosen experts to advise you on what is best for your project!

Typical steel thicknesses are:
10mm base plate
6mm hull sides
5mm cabin side
4mm roof

Therefore a narrow boat built with same would be classified as being 10,6,5,4.

Your canal boat builder will be able to explain the steel specification that they use.