http://www.hansonclan.co.uk/images/R...lass_image.htm
I also noticed that on the T-class submarine they called it a Search Periscope instead of an observation periscope like we do. Look at this diagram I found.
The diagram on the T boat calls it a Search Periscope instead of an Observation Periscope. Don't know why.
http://middle-watch.com/WWII_Radar.htm
A look at what British radar control rooms looked like.