Wednesday, 11 August 2010
The Concrete Power of Roman Aqueducts
Quite a few people on my tours at Vindolanda ask me about Roman concrete. I've tried to find out about it as best I could. (Click on the "concrete link" for more information.) The video clip above describes the process briefly.
I got into discussion with one chap, a civil engineer, the other day, who has worked on a variety of civil engineering projects past and present. He is currently working on a project - something to do with the spire at Westminster Abbey. We had a chat about Roman methods of making concrete. I naturally talk about "opus signinum" which is a special waterproof concrete (broken up tiles mixed with lime mortar) which are still in evidence in the floors of the bathhouses. There is also the traditional Roman lime mortar concrete (the Romans were the first to invent concrete...which aided their imperial expansion plans massively). This film here shows that even their normal concrete, itself, is waterproof and goes on to show how the Romans built aqueducts and how they could bring in loads of water - 300 gallons per head per day in ancient Rome which is more than five or six times what modern day cities manage. So "what have the Romans ever done for us?" They gave us: concrete!
There are two bathhouses at Vindolanda. I show the visitors the more modern one (built c. AD213 for the Fourth Cohort of Gauls) and it is very near Stone Fort II...quite near part of an exposed aqueduct. So far so easy as to how they got the water to it. The big conundrum (maybe) is the older bath house at the far end of the site built for double the number of men (1000) c.AD100. It is not near a visible water source. It was demolished by the Romans themselves a bit later on. It had become outmoded and was too big for later garrisons. How did they get their water there? Well, having looked at this film where it talks about transporting water from 40/50 miles away, via aqueducts, into the heart of Rome.....then a few extra yards at Vindolanda isn't going to make a lot of difference quite frankly. Case closed. In fairness the archaeologists did find long alder pipes in 2003, fitted with oak pegs, where the water was still running through them almost two thousand years later. Maybe the water got to the bath house via a mixture of pipes and aqueducts. It definitely got there somehow as 100 men got to be clean all in one go!
A couple of years ago I read Robert Harris's superb novel, Pompeii, and its link is here. The whole premise of the book is built around the magnificent engineering of Roman aqueducts. The link, I've highlighted, is well worth the read as it is designed for book clubs. So now when I think of aqueducts I think of his book and the breath taking aqueduct at Segovia, Northern Spain. I can't remember whether I got my photo snapped there. I'll have to rootle around my old photo books. (Strawberry Jam Ann has just reminded me of a marvellous, world famous restaurant there where I was lucky enough to dine once - el meson de candido...The roast suckling pig is famed across Spain!)
I'm away from my computer over the next few weeks for a variety of reasons. I'll continue posting but may not be able to get back to you/your comments for a wee while. Happy Summer Hols everyone!
P.S.: Looks like an interesting programme on archaeology will be shown over the next month or so. It's called "Digging for Britain" and starts 9pm on Thursday 19th August on BBC2. It is shown at 10pm the same day on BBC HD for those of you with programme clashes! (Must admit that the silly but fab "Mistresses" is on at 9pm. !!)