Reading through this thread with interest. I well remember the old class 116 DMUs we used to travel on when growing up, late 1960s, and through the 1970s. The guards van, has we called it, has massive space available. My mother would take the pram, later the pushchair, into this area without any problem. Generally she was only travelling between Porth and Pontypridd. Sometimes to Cardiff and Barry.
Roll forward to the 1980s, one anti-rail government and an army of accountants. The guards van was not included in the new Sprinters, and they were cut back to two car formation. A similar thing happened on the mainlines where locomotive hauled coaching stock was replaced by these monstrosities. All in the name of profit.
Take me back to the 1970s, two three car class 116 units with a guards van in each set, and redesign the present monstrosities. If the guards van had been kept, most of todays problems, wheelchair vs. buggy would not come about.