A technical question about the hull's plating

[laurent Gontier-Versailles]

Hi to all ,
I'm modelling Lucy right now at the 1/100 scale.
I got stuck on some plating's items , as I see that there are a few manholes on the hull plating , below the waterline.I saw this on the shell expansion plan I'm studying as I will model the plating.
My question is :
Why did they put manholes on the outside plating , while I presume that there must be a lot of inspection manholes on the tanks top , inside the ship.
If these manholes on the outside plating did exist , were they tightened by bolts or were they riveted ?
Were they flush with the surrounding plating , or were they "in" or "out" ?
I have to say that I'm scratching the back of my head for the moment...

Laurent

PS : For the american among us , a very happy 4th of July...

 

[Bill Sauder]

Hi Laurent,

The manholes on Lusitania were flush, so all you would see is a circular groove at the edge. They were bolted in place.

Typically, double bottom tanks have two manholes, One in the outside shell, and one on the tank top. They are arranged to provide adequate ventilation while men are working in the tank, and to facilitate access to the interior of the ship, the tank, and the dry-dock, so that workers can go from the ship's interior to the dry-dock floor without having to climb up to a gangway and then back down.

Bill Sauder

 

[laurent Gontier-Versailles]

Hi Bill ,
Many thanks for your answer about the use of these manholes.
I have to say that this was a "premií¨re" , as I never saw such a feature on other ships...
I know from experience that some sea chests , when opened , indeed allow people to climb into the ship , but I never saw such manholes before.
You talk about circular groove.
Were these manholes plain round or were they ovally shaped ?

Laurent

 

[Bill Sauder]

Hi Laurent,

I spoke too quickly when I said "circular groove". They are not circular, nor are they oval.

They are semicircular ends separated by a rectangular center section, in other words, a circle that has been pulled in the middle.

The plans you are working from (Lusitania Shell Expansion) are distorted, the vertical to horizontal scales being in the ratio of 2:1. If you keep this in mind, you can get a sense of what the looked like from the plans themselves.

Bill Sauder