Before automatic barriers, what would have been the arrangement for a level crossing on a 4 track line. Assuming that the road was normal width the gates wouldn't have been wide enough to provide a barrier across the railway line. Would they have had to have been divided into two crossings?
No set practice, varies from location to location.
Here in Hull Walton Street crossing is the opposite, a double track line across a dual carriageway, with each carriageway having its own set of barriers, and regarded by the railway as two separate crossings.
In your scenario the barriers would normally be the standard road width, and as a result would not completely obstruct the railway when opened to the road. This is irrelevent really as the signals are what protects road veheicles using the crossing and not the barrier.
I can'y actually think of any level crossing on a 4 track line. There is one north of Peterborough but that is effectively two parallel double tracks so presumabley when gated it was two sets of gates. The only other that I can think of is Bollo Lane in West London but that is again two double tracks that are close to each other. Can anybody come up with a location for a level crossing on a 4 track line.
A lot of double track crossings had single gates long enough to cover both lines even across a diagonal. They made one hell of a crash when they closed. So a pair of gates could easily cover a four track main line.
There's a crossing at Melton near Hull over three tracks (used to be four) but that's auto-barriers which operate as mentioned in my earlier posting, in other words do not fully barrier the railway when open to road traffic. You can just see the crossing beyond the semaphores in the background of this image.
There's also a manually operated, gated accomodation crossing at Copmanthorpe (near York) over the four tracks of the electrified ECML.
4 tracks for the East Coast main line, a wide gap then 2 tracks for the Midland. A span of probably around 80 feet. There were 4 gates of about 10 feet wide. These were replaced by full barriers in later years. A quite daunting crossing when travelling by car as traffic very often backed up on to the crossing during busy times due to the close proximity of the junction with Lincoln Road.
South of Spalding station, Winsover Road, there were 8 gates altogether,
4 for the main Boston - Peterborough route and 4 for the M&GN Spalding - Bourne.
From my childhood memory, there used to be a 4-track crossing adjacent to Grimsby Town station, with two separate sets of swing gates operated with hand cranks from the same signal box. As this was in the centre of town with a lot of pedestrian traffic, it was quite fascinating to watch them in operation. Nowadays it's a 2-track crossing with automatic barriers.
Somewhat off-topic, I recently visited the Isle of Man and rode the steam train from Douglas to Port Erin. The southern half of the line was closed in 2003 and completely rebuilt with welded rail and automatic crossing barriers. It rather spoils the experience of riding in a vintage steam train with wooden carriages, to hear the siren-like wail of automatic crossings, not to mention the lack of jolting and rail joint noises! Thankfully, the MER and SMR retain their vintage ride qualities.