HDPE Narrowboat

Mothership Marine does 2 things – 

1) Builds beautiful solar Electric Narrowboats using reclaimed timber which gives a upmarket country cottage aesthetic. 

2) Builds and sells full electrical systems for other parties to install. Items include Hight Torque electric motor, solar, generator, batteries, Victron equipment etc. We can also help with the installation.

We like innovative projects and one such example is a new narrowboat made from HDPE for Stuart Burton. Like all projects there are advantages and disadvantages. 

What is HDPE and is it a good material for building boats out of. HDPE is High Density Polyethylene, the same material pipes, buckets and garden furniture is made out of.  Here are a few more comparative statistics.

HDPE has a Density of 0.95 g/cm3, a Tensile Strength of 30 N/mm2, a Modulus of Elasticity of 0.565 – 1.50 GPa, a melting point of 135°C

Steel has a Density 7.85g/cm3, a Tensile Strength 485 N/mm², a Modulus of Elasticity of 210 GPa, a melting point of 1350-1530 °C

Aluminium has a Density 2.7 g/cm3, a Tensile Strength of 90 – 140 N/mm2 a Modulus of Elasticity 69 GPa, a melting point of 660°C

To answer the first question, is it a good material to build boats out of? Yes is the answer https://tidemanboats.com/ already to build high quality and very tough workboats.

But will HDPE make a good narrowboat. Narrowboats don’t have to be steel. Sea Otter Boats made very good aluminium narrowboats. Many of them are still operating today and look great. They don’t rust. 

It is possible to build a boat from HDPE however because of the material characteristics there is a need for a radical rethink of the structure. It needs to be thought of more like a modern monocoque car body rather than the classic chassis and coachwork. The structure is more complicated but with computer aided design and cutting it may even save time.

It’s an interesting project and one we are very proud to be involved in. Stay tuned!