David Hibbert

There are many locations where Mk1 (with copper catenary) join Mk3A or B (with aluminium -AWAC- catenary) but the designer has to ensure that the AWAC catenary does not come close to copper catenaries, as the copper washing from ther copper catenary will corrode the aluminium of the AWAC catenary.

These drawings are correctly known as CROSS SECTIONS. Every mast/portal/headspan location has one.

The welded rod portal was a spare new one made up of metric angles and rod but generally as per the original Mk1 drawing in the 3000 series.

I walked have the GE lines many times and this photo looks more like the Country end at Shenfield. It certainy is not Ilford.

The higher contact wire was not to facilitate pullingthe coal forward in tenders, though that would have been a bonus, the higher wire was tom allow the firman to take on water. Level crossings over main roads also had higher contact wire to allow double decker busses to pass.