Facts & Falacies

Facts & Falacies

Ferro-cement boats

A 30ft 8ton displacement sailboat

Built in ferro-cement weighs 8tons. A 30ft 8ton displacement sailboat built in GRP/FRP weighs 8tons. A 30ft 8ton displacement sailboat built in wood weighs 8tons.

GRP/FRP (glass or fibre reinforced plastic)

Is a method of construction developed from SRP (steel reinforced plaster, now known as ferro-cement).

The advantage of the action of Osmosis on ferroboat hulls

Is reversed to a disadvantage on GRP/FRP constructed hulls.

A wood constructed boat

With a hole in it will sink at the same rate as a ferro-cement one.

Nothing lasts forever

Even a ferroboat.

The biggest disadvantage of a ferro-cement hull

In the eyes of the surveyer, is it's almost unique individuality.

An estimated 11,000 Hartley ferroboats

Have been built worldwide.

The first solo crossing of the Tasman Sea

Was made in a home-built ferro-cement Hartley 'Tasman 33'.

The earliest known ferroboat still in existence

was built by Lambot in France in 1848.

The country to have built the most vessels in ferro-cement is the UK

An estimated 9 million tons were built in the period Sept 1943 to May 1944 alone.

Boats have been built in ferro-cement from 10ft to 20,000 tons

For amateur construction using the standard 'Hartley truss frame', method around 25ft is about the smallest that can be built (smaller requires other methods).

The smallest and largest 'Hartley ferroboats

That have been designed are a 12ft dinghy and the 130ft Steam Yacht 'Blackwater Lady'.

The British designed a 120ft submarine in ferro-cement.


The oldest ferroboat still afloat and in daily use

Is probably the 'Violette'. Built in Faversham, U.K. in 1917 as a coastal freighter. She plied her trade for around 30 years before her machinery wore out and was retired. She is now a floating clubhouse on the Medway River.

Want to know more about Ferrocement?

The information and comments given on this 'World Of Ferroboats', website are based on first-hand experience gained by the contributors over many years of use, designing, surveying, building and repairing ferro-cement boats.