My friend Rob has very kindly given the fort a copy of Webster.  Webster is the authority on the Roman Army and is incredibly readable.  Much better than Gibbon whose book is like using a cheese grater on marble.  In my very few down moments I am working my way through Webster and am finding it fascinating.

This week I have been reading about camps, forts and fortresses.  What I have found is that there is no aspect of the Roman military that they did not think about in incredible detail.  The ditches around the fort being no exception.

One of my faviourate books is “The Use of Weapons” by Iian M Banks.  In this book the principle character has a gift for turning everything he sees into a weapon, which causes the unfolding of his mind.  The point I want to draw out of this is that the Romans also had this ability, they could see an opportunity and develop it powerfully.

The ditches around the Lunt Roman Fort are powerful, deceptive and terrible.  On first inspection it appears to be a normal two stage ditch.  the idea being to cause an obstacle to siege machines and infantry.  But after a short inspection it seems easy enough to get down and then the bank closest to the fort is smaller than the decent.  As long as you can evade the caltrops  and the ankle breaker you can easily climb out and prepare to attack the ramparts.  But this is the deception.  The Romans withhold their missile fire, from their spring guns amongst other weapons until the ditch is full of enemy and then open fire.

The spring gun is a torsion catapult firing a bolt at about two hundred miles an hour.    The from the ancient records these could kill up to seven men with one shot.  A conservative estimate of the rate of fire is maybe three shots per minute meaning twenty one dead in a minute.  If these weapons are masses and co-ordinated they can cause chaos in the ditch.  The effect would be chaos and very soon the attack would collapse leading to a general rout.  At this point the genius of the ditch network becomes horribly clear.  The ditch was easy to get into but is in fact at a very steep angle and a serious obstical to escape.

It is almost as if the fort was designed to provoke attack.  We have no evidence that it was ever attacked but if it were the ditches would invite the celts to attack and then prevent them from escaping.