The de-icer used on the bridge shouldn't be ordinary road salt - Kilfrost or Procoat are the standard low corrosion alternatives, but I expect road salt has been washed down onto the bridge from Quernmore Road.
Interesting, how do these railings help - or is just to keep people off the weakest part of the structure?
Here's an article on WGC
I can't find an official NR reason but assume the distribution of weight is to the centre.
Thanks Robert. That certainly looks like the answer.
On a related note, does anyone know why a warning and cross hatching in red paint have been put on the bridge cautioning against more than 40 people being on it?
Who, upon approaching the bridge, is going to pause and think - or count - "hang on there looks like there might be about 38 or 39 people on the bridge, I better not enter just yet?"
Incidentally, I assumed the metal bars were because buskers had begun sitting against the wall in some of the summer evenings at commuting times and they were a deterrent.
As discussed further up the thread, the barrier came first, the hatching has appeared in the last few days, and both are measures designed to limit the load on a weaker-than-desirable structure. This newspaper article is about the same problem, now fixed, at Welwyn Garden City.
Thanks - I did read the article. Let's hope if it needs replacing (which it does) it doesn't take six years from now.
I'm just unconvinced that anyone is going to think twice about walking onto/across the bridge because there may be close to 40 people already on it. Joe Public doesn't know what 40 people in a small area actually looks like.
So I took a look (well, the steam train intended this morning was diesel-substituted, but I wanted the walk). Looking up from the platform, that whole span of the footbridge is simply supported by brackets springing from the substantial girders that support the ticket office. There is no horizontal girder at the north side to support the footbridge, underneath where the barrier has been fixed, and there's considerable corrosion visible.
Peak loading will be from trains unloading in the evening rush hour, and people are more likely to be intent on getting home rather than standing chatting or reading signs. The narrow gate at the top of the steps from the platform (strictly one person at a time) restricts the flow onto the hatched area. That is 25 paces long, and narrow enough that some people will wait till the wider part before they overtake slower walkers. So I'd expect the likely real-life loading to be about 30 people maximum. But I agree, how enforceable will it be?
I recall that Great Northern will be staffing Harringay station all day 'by September 2015' according to the targets they published when they took over the franchise - will crowd control ("Stand clear of the doors hatchings") be added to the job description, I wonder.
Update: some of the corrugated cladding behind the new barrier has been removed, replaced by plywood boarding for weight reduction I suppose. The '40 persons maximum' signs have been dutifully replaced.
As has the 'Meeting Point' sign. Where it was before, opposite the ticket machine. Plumb in the middle of the hatched (and narrowed) area. Doh!!
If it has to go back, why not put it on the eastern part of the bridge 5 metres away which is full width without a weight restriction?
The footbridge will be closed 00.00 Dec 25 to 05.00 Dec 27 for strengthening work. More details here (thanks to Konrad).