If you take a close look a level crossing, you might’ve noticed something about the boom barriers used to prevent cars driving onto the tracks. Some are made of metal.
Aluminium channel to be specific.
And others are made of timber.
Two separate pieces, tied together to form a truss.
So what gives?
The answer is above you
Look up – at the 1500 volt DC traction power used to power Melbourne suburban trains.
Level crossings on the suburban network use timber boom barriers, because if they get pushed into the overhead wires, the last thing you want is something metal forming a conductive path.
While V/Line and freight lines are free to use the simpler and cheaper metal boom barriers, as they don’t have the same electrical safety concerns.
Just the usual worries about vehicles driving through them.
Footnote: swapping metal for timber
In 2012 suburban trains were extended to Sunbury, by electrifying the existing railway.
As a result every level crossing between Watergardens and Sunbury had to have the metal boom barrier arms removed.
Google Street View 2009
And replaced with timber ones.
Google Street View 2018
And on language
In Victorian the official name for the arms that lower to prevent road vehicles from crossing the tracks is “boom barrier” – not “boom gates”.
The term boom barriers is synonymous with the term level crossing gates. It is used to denote flashing lights and half road boom barriers.
Crossing gates that swing across the tracks and are operated from a signal box are called “interlocked gates”.
While gates that need to be moved by hand are called “hand gates”.
Fiberglass ones are type approved for use on the Metro network. So there are actually three types available.
You will find fiberglass ones around the country areas if you look, and the odd ball crossing at Oakview Lane (Mt. Ararat Road) between Pakenham and Nar Nar Goon, which was transferred from V/Line to Metro but not changed out to wooden booms because the wires stop before that crossing.
Cheers – I’ll have to keep my eye out!
I do have a photo of the Oakview Lane level crossing at Pakenham.
I didn’t know about the change of line status to Nar Nar Goon. I need to investigate east of Pakenham.
Well, who would have guessed that. Most interesting.
The best boomgates is one which does not exist!
That’s a clever one.