i). For some reason the KTMB says that train the 36 will reach Bangkok at 1.30pm. Bangkok time, while Thai railways insist its 10.30a.m Bangkok time. Which is true? The difference is Thai railways claim the train 36 will leave Hat Yai at 6.45pm but KTMB says 9.15pm...can you please advice?
Both true! Its depend on time taken while crossing Malaysian-Thai border. Coach from Malaysia will be attach to Bangkok train which depart 3 times daily from Hatyai. First train will be arrive Bangkok at 1030 athers will be later. That meas if train from Butterworth do not delay, it will be attach with the first train to Bangkok, but if delay it will be attach to the next train.
ii). Are they usually long delays during the whole trip? Yes. same from Bangkok to Hatyai. On Feb this year I catched the 3.00 pm train from Bangkok and arrived Hatyai at 1.00 pm instead of 9.00 am on the next day
iii). Can we not change the 2nd class sleeper to seats during the daytime, but rather all the way being a bed fm Butterworth to Bangkok?
Cannot. From Butterworth (about 3.00 pm depart), the coach already seating position. Only after depart from Hatyai (at night), the seats will be change to berth. No such workers on board from Butterworth to Hatyai to change the seat to berth. Any way you may request it on board if you want to. Depend how luck you are!
Anyway travel in train is very interesting if you don't bother about time.