Oh damn I deleted my own post, gt it back again!
I have a kraut SS document here assessing military feasibility of combat in England heres what it says about londonistan:
"London is bounded by the Chiltern hills to the north, Reading to the west, and the North Downs, or the High Wald to the south. Its population has everywhere merged with that of london itself. The more heavily built up urban areas display a strong individual presence in its northern, eastern and southern parts; they are generally distinct from the commercial and administrative center of the city and the purely residential eastern sector. Only in the heart of the city have high rise buildings been constructed; further away from the core, lines of identical houses stretching monotonously across the landscape are everywhere the norm.
The Thames begins to widen as soon as it enters london. It is 400 meters wide in The City and 8oo meters at the east end. Downstream from the Tower, the docks extend continuously as far as Woolwich. Huge gristmills, gasworks, electric power plants, oil storage tanks, oil refineries, cement factories, paper factories line the river. The estuary begins at Gravesend (35,5000 population as of 1939). Gravesend is where pilot boats begin escorts. The main oil storage plants are located at Thameshaven and Shellhaven on the north bank beside gravesend. Numerous old port towns, harbors and industrial settlements can be found on the estuary, here the Royal Navy has many small shipyards, workshops and warehouses. Mechanical industries, paper und cement production, engine manufacture,flying boat production, chemical plants (including still usable great war poison gas facilities) are found here.
Military evaluation
There are three major to be taken into account as major obstacles when considering troop deployment in a north south direction are concerned;
1) The broad river thames estuary- in places widened still further by soft ground with few roads and guarded by numerous fortifications
2) The huge city and suburbs of london whose central districts have narrow easily defend-able streets that would make tank deployment unwise.
3) The upper thames which is still wide enough to present considerable difficulties if motorised units attempt to cross even with swimming wagons (schwimmwagons).
The west-east line formed by these three obstacles has the potential to play an important role as a major defensive barrier. Its strength is increased by the lines of hills to the north; they run from south west to north east and also serve as important vantage points. Likewise london the line s of hills mentioned and of course the river lea all form a significant barrier running in an east west direction."
