Are Iron hulls good or bad?

[Vanessa Barns]

I have been looking at different river & canal boats that are for sale & I came across a barge that was listed as having an iron hull. Does anyone have any advice or knowledge they can share with me about the benefits or drawbacks of an iron hull compared with steel?

Thank you, Vanessa

[MtB]

Any boat with a riveted iron hull is going to be 50 years old or one helluvalot more.

 

Wonderfully beautiful (usually) and you'll need deep pockets for maintenance.

 

Does that help at all?

 

 

MtB

[Neil2]

In theory iron is more prone to rust than steel and also, in the modern world, harder to repair. I may get an argument on both those points...

 

Iron is heavier than steel which may or may not be a good thing.

[alan_fincher]

Iron is heavier than steel which may or may not be a good thing.

 

Assuming you mean "more dense", I'm not convinced.

 

OK, I know all such materials have a range of density values.

 

But charts like these put wrought iron as slightly less dense than steel, rather than more dense.

 

Linky.

 

EDIT: But the density differences are small enough to be meaningless in barge or narrow boat construction - an extra 1/16" in plate thickness would make far bigger differences than a choice between iron or steel.

Edited January 4, 2015 by alan_fincher

[Bee]

Iron is a good material but as MtB says it will be old. You say barge. There are a good many Dutch barges around built pre 1st world war that are probably iron, It depends entirely on what a survey shows, I can think of a few boats that have had the entire bottom renewed at some time and could be perfectly well overplated before starting the whole procedure again. On the other hand there are boats going around with half a ton of ill fitting patches slapped on all over the place. A hull survey by an experienced surveyor is essential, not just a look over by a boatyard.

[luctor et emergo]

Iron rusts, on the surface, but does not rot like steel. Iron can be welded,just like steel. Maintaining an Iron hull is no more expensive than maintaining a steel hull. Recent steel, see less than 20 years o;d, can be of very dubious provenance. Plenty of 20 year old boats that need plating over out there. On the other hand, if an iron hull has lasted over 50 years, and passes a survey ok, you are laughing.

 

Dont listen to the nay sayers trotting the party line. Iron is better than steel. Just dont bother fixing it with rivets...

[John V]

I go with Luctor on this one however any repairs will be, of necessity, in steel. Steel and iron do not make the best of bedfellows.

 

I had major corrosion problems due to iron frames and steel plating, although it was on an 80 plus year old boat !!!

[waterwitch]

The boat we have live on and cruised for the last 18 years is lowmoor iron, built in 1885. All the rivets have been welded and there are a couple of steel over patches on her. Still in very good condition. She is an ex Whittaker's tug...originally steam, converted to Gardner diesel in the fifties.

[Vanessa Barns]

The iron hulled boat I saw is a small barge built in 1915, it had a hull survey in 2013 but it doesnt give any more details than that (& yes it is beautiful in side). I wanted to find out some information about iron hulls from those who live with them to see if this is one worth following up for more information.

[koukouvagia]

There will be very few boats of that age that will not have needed work on the hull at some time. There is nothing intrinsically problematic with iron boats. It's all down to how well they've been maintained and how strenuous a working life they've had.

For example, our 1912 butty needed extensive re-footing (replacing the bottom 12 inches of iron with a steel plate all round the boat), but the 1928 motor, which had had a fairly easy working life, needed very little attention - just a few small patches. At its last major hull survey last year, a few more weak spots had to be dealt with and about a dozen rivets had to be welded up because they were in danger of popping,

So, as others have said, keep on top of the maintenance. Once any thin spots have been repaired with they'll be OK for years.

[Murflynn]

 

 

Iron is heavier than steel which may or may not be a good thing.

nonsense. the weight (density) of iron and steel is 7850 kg/cu.m. - they are exactly the same.

many old Dutch hulls (100 years or more) are built of quite thin iron plating, say 5mm or 6mm.

I know of several centenarians that have had minimal repairs.

[bargemast]

Between '75 and '83 I owned a Dutch Groninger "Oostzee Tjalk" which was a heavy built Iron Tjalk of 1897, before the 2nd W.W. when times were hard this barge was in the Baltic trade and had no engine at the time.

 

She was motorised after the war and all the sailing gear was removed, the surveys I had done on her showed her still being in perfect condition, which a few patches over places that had cracks underneath, as in winter Iron is brittle and doesn't like to deform, so if something is hit hard enough, instead of leaving a dent, it will crack

 

Apart from that she was still almost as good as she was in 1897, and is still afloat now and is a hotelbarge around Venice in Italy.

 

But that doesn't mean that all Iron barges have survived the same, so a serious survey is very important before you invest your money.

 

Peter.

[Neil2]

 

Assuming you mean "more dense", I'm not convinced.

 

OK, I know all such materials have a range of density values.

 

But charts like these put wrought iron as slightly less dense than steel, rather than more dense.

 

Linky.

 

EDIT: But the density differences are small enough to be meaningless in barge or narrow boat construction - an extra 1/16" in plate thickness would make far bigger differences than a choice between iron or steel.

Dense is the right word - exactly how I feel right now.

 

What I was thinking was in boat building iron is "heavier" than steel, presuming the plating is much thicker. But I wonder now if it is.

 

The trend in recent years towards thicker and thicker steel plating on narrowboats means most boats are overbuilt, Presumably cargo carrying boats from the past would have wanted to maximise their payload so the iron plating wouldn't have been any thicker than it needed to be. So could an old iron boat actually be lighter than a modern steel boat?

[alan_fincher]

The trend in recent years towards thicker and thicker steel plating on narrowboats means most boats are overbuilt, Presumably cargo carrying boats from the past would have wanted to maximise their payload so the iron plating wouldn't have been any thicker than it needed to be. So could an old iron boat actually be lighter than a modern steel boat?

 

I think (but I'm not completely sure!), that most riveted working narrow boats didn't tend to have much of the hull plated at more than 1/4" thick, (so 6mm in modern terms). Certainly there was no equivalent of baseplate at 10mm thick or more.

 

From memory (I can't find the drawing at the moment), boats like Sickle unusually has round chines that were a bit thicker (I think 5/16"), but the sides above this were specified I think at only 4 / 20", (why that's not written as 1/5", I don't know!) - that is only 5mm, so shares something with some Springers!

[David Mack]

If the boat ticks all the right boxes, I can't see why whether it is iron or steel should matter in your decision whether to buy it.

[Timleech]

 

I think (but I'm not completely sure!), that most riveted working narrow boats didn't tend to have much of the hull plated at more than 1/4" thick, (so 6mm in modern terms). Certainly there was no equivalent of baseplate at 10mm thick or more.

 

From memory (I can't find the drawing at the moment), boats like Sickle unusually has round chines that were a bit thicker (I think 5/16"), but the sides above this were specified I think at only 4 / 20", (why that's not written as 1/5", I don't know!) - that is only 5mm, so shares something with some Springers!

 

I have copies of several original shipyard drawings for my boat, most of the thicknesses were specified in 20ths of an inch, 1/4" is 5/20ths etc.

 

As for iron vs steel, iron will generally corrode more slowly than steel, although both terms can cover a variety of different products.

Some iron welds easily. Some needs special rods to avoid a brittle weld. Some is heavily laminated, so there's a risk of welding attaching only to the top layers, so it's not always straightforward but most of the time not a problem.

 

Tim

[Loafer]

All the wizened old giffers that I've ever questioned always said that iron was superior. They did all have oil-spattered engine rooms though (not that oil-splattered engine rooms are bad, it's just that I can't have one).