Stations and Water Line references units question

[galgot]

Hi,
I'm trying to decrypt a manufacturer plan.
Can W.L. (Water-Line) and Sta. (Stations) references use different units ?
For example, I have distance from W.L. 0 to W.L. 200 different from distance from fuselage Sta.3000 to Sta.3200.
Are Stations refs always in inches ?

 

[TomS]

Yes. The number of stations in a lines plan can be arbitrary, not based on a specific measurement. It's fairly common to simply specify 20 stations, for example, and define the spacing between stations based on the ship's length.

 

[galgot]

Thanks.
Was afraid that plan was completely distorted.
I suppose W.L to W.L 200 are 200 inches then ...

 

[TomS]

I just realized I may have led you astray. I was thinking about naval architecture, where Stations are totally arbitrary. In aircraft, they aren't done quite the same way and should be based on measurements in inches (in US plans). They start from an origin point, usually on the centerline of the aircraft, somewhere near the nose (but sometimes ahead of it), and usually on the ground.

http://www.aerospaceweb.org/question/design/q0289.shtml

 

[galgot]

Ah thanks again
Well I'm confused... if all is in inches (it's a US plane indeed) W.L to W.L 200 and Sta.3000 to Sta.3200 should have the same length , isn't it ? Don't understand, the plan doesn't look distorted at all.
Hence my first question : ever saw W.L. (Water-Line) and Sta. (Stations) references use difference units ?