Your correct in every aspect. It is the former “A” bridge of the “four Bridges system” that crossed Birkenhead docks. The bridge was constructed just after the First War, I think, and was scrapped about four years ago and replaced with a new lifting bridge. This was, is, the major route from Wallasey to Birkenhead and was an absolute nightmare to cross on a motor bike especially when it was wet and force six and above, was blowing down the East Float. This was made worse because the roadway consisted of granite “sets” and railway lines, these had to be crossed at 90 degrees or thereabouts otherwise you would go into an uncontrollable skid. The bridge deck was made up of steel plates, railway lines and wooden blocks making it even more deadly, you just hoped that the vehicles behind understood this, most did of course thankfully, but there were times when I got off and pushed the bike across. It was a dangerous place to be with a mixture cars, wagons, and trains, and me on my 1947 BSA C11 or Honda 50 super sports with full racing fairing!