- Nov 2008
To be honest, I had never heard of the Car Dyke until it was discussed here.
To my surprise it is huge - 12 to 17 metres wide, 3.6 to 4.4 metres deep and 92 km long. Its volume is 3.3 m cu metres and by comparison Offa's Dyke is (only) 0.8 m cu metres. It is easily the biggest, longest ditch in England - vallum at Hadrian's Wall is 1.3 m Cu metres.
Clearly there is no chance that it was constructed by the A-S in 5 or 6th Century.
I am grinding my way through Storr's book but I can not help asking why this and other dykes could not have been constructed with certain purpose in mind eg water transport or drainage in the case of Car Dyke and then found a second use as military tripwire.
If you study the maps in Storr`s book, and also other maps and details of how much the coastal region of Lincolnshire was partially underwater at that time, you will see as Storr said that the dyke was indeed defensive and superbly situated. Clearly it wasn`t a transport canal, being too close for comfort to attention from Saxon pirates. Moreover, it would not have been needed as a transport system simply because, as Storr said, Ermine Street was just to the east of the dyke. You will also no doubt have read that the remains of a number of forts have been found along the length of the dyke. Clearly a splendid example of Roman military engineering, neatly connecting the Northumbrian coastal watchtower system with the Saxon Shore defences and protecting the rich agricultural hinterland of Lincolnshire.