The "Starved Cow" effect, how do you prevent it?

[MarkOHara]

When it comes to steel boats one thing I cannot stand the sight of is the "Starved Cow" effect where you can see all of the ribs through the skin. This gets worse as the boat ages and unfortunately it makes a lot of now historical boats look unsightly and on their last legs.

I always thought it was just the hull getting pounded from rough seas but a yacht finisher told me it has to do a lot with weather too and the expansion and contraction of the plate. He just finished a ex- Royal Navy (1968) to Yacht conversion recently and the fairing compound was 50mm (2") thick in some places. He reckons it will have to be done again in another 10 years.

Boat builder Charlie Ward tried to avoid it by using heavier plate and the addition of longitudinal stringers when building S/B Juno (launched 2000). So far it looks like his efforts have been successful.

Below the "starved cow" effect

Compared to S/B Bruno

 

[jehardiman]

Heavier plate and closer frames is about it. Note that wave slap is ~2000 to 4500 psf. But I wouldn't expect much without significant expenditure of time, weight, and money; the photo below shows the USS IOWA bow plating...that's 3/8" STS...75 ksi yield strength.

 

[wet feet]

A small correction about Juno,the boat was completed by Charlie Ward but the hull construction was by George Prior Engineering as they had the steel working ability.Which has been amply illustrated above.

 

[MarkOHara]

A small correction about Juno,the boat was completed by Charlie Ward but the hull construction was by George Prior Engineering as they had the steel working ability.Which has been amply illustrated above.

Thanks for that! Are George Prior Engineering still in operation? I see a history for them on Google but nothing up to date.

 

[Tiny Turnip]

Personally, I really like the hungry horse' effect, particularly on naval vessels and working ships. It's an aesthetic that is an honest result of the material and construction, like the planking lines on a timber vessel.

 

[MarkOHara]

Personally, I really like the hungry horse' effect, particularly on naval vessels and working ships. It's an aesthetic that is an honest result of the material and construction, like the planking lines on a timber vessel.

Perhaps your "hungry horse" is a far better adage for the condition. When a horse gets that hungry and long in the tooth you just put it out to pasture. I appreciate your opinion but I'm not a fan. I'm a boat builder to trade myself, but I specialize in wood and composites and I find the older wooden barges far more pleasing on the eye.

 

[Ad Hoc]

Frame spacing, long.t spacing, plate thickness, and of course the welding sequence all play a major part.
Too much heat on thin plate that is widely spaced between stiffeners, ...is not a combo.

 

[baeckmo]

Frame spacing, long.t spacing, plate thickness, and of course the welding sequence all play a major part.

Add curvature between long:s.

 

[Ad Hoc]

Add curvature between long:s.

That too

 

[waikikin]

Perhaps your "hungry horse" is a far better adage for the condition. When a horse gets that hungry and long in the tooth you just put it out to pasture. I appreciate your opinion but I'm not a fan. I'm a boat builder to trade myself, but I specialize in wood and composites and I find the older wooden barges far more pleasing on the eye.

Agree with the "Hungry Horse" analogy,... alliteration is always awesome

Jeff.