Am i right in thinking that there is no 1st class cabins on the train from Bkk to Butterworth?

I 've heard that the 1st class cars only go down as far as Hat Yai.  Is this true?

When I caught the train to Singers from Bkk etc, I believe that the one from Hatters to Penang/Butterscotch only had 2nd/3rd class. The only time I did the Hat Yai to Penang was on a bus , bizarrely. I would take a 5th class carriage ( if they existed ) rather than a minibus/bus again.

Penang/Butterscotch

Surely you mean Butterworth don't you,  Bonachot?

I like Butterscotch a lot more. Can we put up a name change suggestion ?                              

You are right in assuming that. I think Malaysia's KTM trains take over from Hat Yai to Butterworth. Only 2nd Class sleepers are available until Butterworth. 1st class is available again from Butterworth onwards.

Vx,  When i went down by train to Penang last Oct.  it was the Thai train all the way there. Yes, even from Padang Besar to B.W.   I can remember when at Padang Besar you had to change onto a Malaysian train onwards to B.W.

I took the train from BKK to Butterworth last week.  I went 2nd class sleeper, but I'm sure I saw passed 1st class on my long trek down the platform at Hualamphong.  It was also the same train from Padang Besar to Butterworth although the staff (and currency) changed from Thai to Malaysian.

NB:  I've travelled first class and can honestly say it is not worth 1 baht more than 2nd class sleeper.

The International Express uses Thai railcars all the way to Butterworth but there is an engine switch at the border.  To the best of my recollection, only four of the second-class sleeper cars are taken south of Hat Yai and no first-class cars make the trek into Malaysia.

I don't know whether this still holds true but previously the International Express (BKK-Butterworth) and the Langkawi Express (KL-Hat Yai) crossed paths at Padang Besar and swapped engines.  The Thai engine is not supposed to travel into Malaysia and vice versa.  This switch always made for a good potential delay as the one train was required to wait for the other.

AFAIK 'ovenman' has answered correctly.  In the mid 90's they did change to a Malay day car train from the border but prior and since it has just been an engine change for the Thai carriages.  And there often is a delay in getting the new engine.

I agree with danbo above. Second class sleeper is better than first class, certainly on the KL to Singapore stretch. I tried first class once and found it gave a poor night's sleep because the births are aligned across the train. In second-class they are in line with the direction of travel and any jolting has far less effect.