Three Bridges (London)

Brunel designed a bridge (aqueduct) to carry the (then) Grand Junction Canal over the (then new) GW branch to Brentford, and a road bridge to carry Windmill Lane over both of them. But that is only two bridges. The third, visible on Google satellite view and street view*, appears to be a footbridge across the railway, with no apparent access to either end of it. Does anyone know any more about that third bridge? It could hardly have been there at all before the railway was built but it appears to have no purpose now either.

* https://tinyurl.com/csuxkvxs and https://tinyurl.com/am5yt5az

 

The third bridge, if it is in fact a bridge, could have been an access to the old windmill based on the Ealing Council pictures.

Better views of the whole thing with the third bridge on this site.

http://www.disused-stations.org.uk/features/windmill_lane_bridge/

 

I reckon the third ‘bridge’ is most likely there as structural support of the retaining walls either side - helping to hold up the canal bank on one side, the road on t’other and the abutments of both ‘real’ bridges.

 

Thanks @Gladiator 5076 for the link to those pictures from various angles and dates. I have visited the site myself a few years ago but I think I should go again and look for myself from as many vantage points as I can reach.

And thanks @Miff; support of the retaining walls does seem the most plausible purpose. But then is it really a "bridge" or are there really only two bridges?

 

I've been looking at some NLS maps. This one https://maps.nls.uk/view/103658198 clearly shows the bridge/support, but this one https://maps.nls.uk/view/102345852 from just one year earlier does not. Maybe the cartographers changed their mind about showing that detail, or maybe someone was worrying around that time about stability and decided that an additional buttress was needed.

 

Interesting aerial view in the BLS tour page if you click on
https://www.branchline.uk/current-fixtures.php
London Railway Curiosities Roundabout day tour