Answered Boiler Room Question


Cam Houseman

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What red paint?
I think he meant directly outside of the boiler rooms. Yes, that indicated where the sea level would be, like how there are (were) numbers at the tip of the bow, counting down from just above the red paint. One to 42. 42 feet above the keel.
OIP.jpeg
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Also, the paint was red, because it was anti-fouling paint, to prevent the water from eroding the paint away.
 
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What red paint?
I was going to ask that myself. I never heard of the waterline being marked (painted) inside. But it does bring up another question. Maybe you or Jim knows this. Did Olympic class ships water line change much between being fully loaded and empty? I know it wasn't something like an oil tanker riding high when empty but how would one know where the waterline was inside?
 
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Cam Houseman

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I think it depended kind of on that, but also the water tanks, I think. The more supplies and water used up, the higher the ship would come out of the water. So they could flood the tanks, pulling Titanic back down to the regular waterline.
I'm not quite sure how to word it, one of y'all can probably do a better job
 
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Stewart Hall

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I think he meant directly outside of the boiler rooms. Yes, that indicated where the sea level would be, like how there are (were) numbers at the tip of the bow, counting down from just above the red paint. One to 42. 42 feet above the keel.
View attachment 49535.
Also, the paint was red, because it was anti-fouling paint, to prevent the water from eroding the paint away.
Sorry for the delay and apparent bad description...I was referring to Titanic Honour and Glory simulation. They show red paint on the lower exposed hull in the boiler rooms. I’ve also noticed this paint on a cutaway large scale model. It seems to match the waterline?
 
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I was referring to Titanic Honour and Glory simulation.
You need to ask the developers of that simulation where they got that from, or why the put that in. As far as I know, there was no reason to have a line painted on the inside hull of the vessel. The waterline is not constant but changes as supplies and coal are used up on a voyage. The change in displacement in long tons per inch immersion (TPI) was listed by H&W, Titanic's builders, at 143.8 tons per inch. At her load draft of 34 ft. 7 in. the ship weighed 52,310 tons. It was estimated by Wilding that by the night of April 14th the ship weighed 4,026 tons less because of the consumption of coal and supplies by that point. The derived a mean draft at the time of collision was therefore 28 inches higher that her load draft leaving Southampton, or 32 ft. 3 in. on the night of April 14th.
 
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Stewart Hall

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Thank you Samuel. I refer to the red paint on the outer hull as being "the waterline" as well. Is that incorrect? Or is it simply more resilient paint on the whole lower hull?
 
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You need to ask the developers of that simulation where they got that from, or why the put that in. As far as I know, there was no reason to have a line painted on the inside hull of the vessel. The waterline is not constant but changes as supplies and coal are used up on a voyage. The change in displacement in long tons per inch immersion (TPI) was listed by H&W, Titanic's builders, at 143.8 tons per inch. At her load draft of 34 ft. 7 in. the ship weighed 52,310 tons. It was estimated by Wilding that by the night of April 14th the ship weighed 4,026 tons less because of the consumption of coal and supplies by that point. The derived a mean draft at the time of collision was therefore 28 inches higher that her load draft leaving Southampton, or 32 ft. 3 in. on the night of April 14th.
Thanks for that info...very informative. I figured it probably wasn't that dramatic as some of the ships I was able to see in my brief stint as a sailor. Some ships I saw looked so high out of the water they looked almost unstable to me. But I'm sure they would correct that later with ballast or something. 28" wasn't very much compared to some of the tanker and cargo/container ships I saw.
 
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Jim Currie

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The short answer, Stewart is NO!

In fact, there was no need for a "waterline" in the boiler rooms. In fact, the tops of the boilers were about 22 feet above the keel and the outside water level at lightship draft was 24 feet. There was always at good head of salt water pressure to prime the sea water pumping systems using gravity. The most important use of sea water was in the ship's fire-fighting and ballast systems.
I think that if there was a painted line inside the hull it was as Bob said, a dado for decorative purposes only, or it marked a particular safety limit or a maximum level for something else. Do you have a picture of it|?
 
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Jim Currie

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Thank you Samuel. I refer to the red paint on the outer hull as being "the waterline" as well. Is that incorrect? Or is it simply more resilient paint on the whole lower hull?
There were two paint systems on a ship's external hull... the anti-fouling and the boot-topping line. The latter ran along the top of the antifouling, separating it from the black of the upper hull. On Titanic, I believe it was narrow and gold.
Most anti-fouling paint was red. It was made up of linseed oil red lead and Iron oxide pigments and contained some very lethal stuff. Originally it extended from the keel on each side up to the light load line. Latterly it extended up to a point which was 1 inch above the summer load line mark. As a matter of interest, the greatest amount of marine growth would be found between the light and loaded water lines.
 
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Interesting. Thanks. I'm sure it was different for different parts of the ocean...ie tropics and such. But how often would a ships hull have to be cleaned for say Olympic class liners operating in the north? On average if there was such a thing?
 

Cam Houseman

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Interesting. Thanks. I'm sure it was different for different parts of the ocean...ie tropics and such. But how often would a ships hull have to be cleaned for say Olympic class liners operating in the north? On average if there was such a thing?
I heard a bunch. They were CONSTANTLY repainting, no doubt the North Atlantic temperature and sea spray did a number.. Was probably a bunch on Olympic
(Makes me think of the picture of the giant scrape along her hull, from the dock.. The captain wasn't used to dealing with a big girl like her ;) )
 
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I heard a bunch. They were CONSTANTLY repainting, no doubt the North Atlantic temperature and sea spray did a number.. Was probably a bunch on Olympic
(Makes me think of the picture of the giant scrape along her hull, from the dock.. The captain wasn't used to dealing with a big girl like her ;) )
Ok thanks for the reply. I should have been more specific. I meant how often did the hull need to be cleaned from marine growth? Like barnacles and such.
 
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