Like I mentioned above there were few SLRs which had cabins for LP/ALP for piloting the Push-Pull train, which had a loco in the middle. This I vaguely recollect from what my father described about the Push-Pull train between MYS-SBC in 1990s. I have seen one but just remember the engine noise in the middle when it passed the LC near our house.
Or maybe few SLRs were built with this shape for some reasons, other members can probably shed light on this.