Krankee:
Here goes.Split coupling is used when the gap between the unit and the trailer is small and where it would be physically difficult to fit between.
Or when the driver is just too fat 
I rarely split couple, but if I do the most important part has to be the trailer brake. And the legs
Just to inform the newcomers, that there is nothing new in transport I found this post earlier. 
Tankerman:
harry:
Tankerman
You were king of the road in those days if drove one
of those. & twenty years old . I don`t think I drove
an artic until I was 23…Stayed at one digs somewhere up North & the
ex-sailor that ran it used to wake the drivers up in
the morning by throwing a great big brass bell down
the stairs…Hi Harry, I think you have misread the posting, I
quoted taskman’s post which included the picture and
was refering to another company which hauled props.
It is Taskman who was 20 in the picture, not me.
I started driving artic tankers in 1968 ( I was 30
the youngest they woulld start)and started on a long
nose Scammell for Gilbraith,My mate told me there was a job going and to get on the tankers was a dream come true. My mate used to bring his tanker home, which was also a Scammell and he gave me lessons on the town car park. When I went for the
job I had to take a test and luckily for me I was the only one who could manage the Scammell gate box so I got the job…Anybody who has handled a gate box will know that you have to go through every gear both up and down. there is no cross gate nuetral, a quick box when you are used to it. The noise through the wooden floor boards was deafening and no power steering. The tanker was very close to the back of the cab because we were sat behind he engine, not over it.
The best way to connect the suzies was to back under the tank but not get too
close to the cab, put the suzies on and then back right under the tank till it clicked onto the turntable. Otherwise you had a struggle squeezing between cab and tank. I have seen more than one driver do this and not had the handbrake on the tank and as soon as they pushed the airline in the tank
ran back off the plate. Good old days, I wonder? I wish I had some photo’s of one of the Scammells. All mine are Buffalo’s, Marathons and Roadtrains.Ok on the big brass bell. You should have nicked it and weighed it in.
All the best. Russell.