Sorry if this is the wrong place for this - anway, a question about rail itself.
In the 1950s rail seems to have been manufactured in two weights; 98 lb and 109 lb. Then 110 lb rail came along; then 113 lb and now 60 kg (125lb?) rail.
My queries are these...
1) Was the 110 lb rail intended to replace both the 109lb and 98lb rail and what is the difference between 110 and 109 apart from 1lb obviously
2) Did 113 lb replace 110 lb or were both rolled contemporaneously, for light and heavy loads?
3) What's the story behind the transition from 113 to 113a rail and was there ever a 110 (without the 'a') rail?
4) Is 98 lb bullhead still rolled?
Sorry for cramming so many questions into one post.
Thanks...