longshotgene Posted February 12, 2009 Report Share Posted February 12, 2009 On Hadrian's Wall the valli have been a hotly contested issue amongst wall theorists. When I did my research on the wall, it was generally accepted that the vallum on either side of the wall acted as a no-go area for civilians and barbarians. I can see this to a point, but I question erosion prevention as well. Could it have been possible that the valli acted as an erosion barrier for the preservation of the wall? This would make sense to a point as the channels created by the entry gates along the wall would act as drainage ditches. Quote Link to comment Share on other sites More sharing options...
CiceroD Posted February 13, 2009 Report Share Posted February 13, 2009 On Hadrian's Wall the valli have been a hotly contested issue amongst wall theorists. When I did my research on the wall, it was generally accepted that the vallum on either side of the wall acted as a no-go area for civilians and barbarians. I can see this to a point, but I question erosion prevention as well. Could it have been possible that the valli acted as an erosion barrier for the preservation of the wall? This would make sense to a point as the channels created by the entry gates along the wall would act as drainage ditches. It is my understanding (and education) that such drainage ditches are only truly useful when there are large expanses of "impervious surface". That is surfaces which prevent rain from infiltrating into the soil naturally. This would be pavement and roofs (mostly). For us it means digging retention ponds for parking lots and subdivisions. For the Romans they used sewers for stormwater in their cities, and gutters for their famous roads. Hadrian's Wall wouldn't have spread much impervious surface over the land. As I understand it they wouldn't have had many problems with erosion undermining their wall as long as the foundation was sound. An exception would have happened if/when the wall would cross a stream. They would have to put in culverts or some similar measure. Are there any examples of this? Glad to see my college education is paying off I'm wondering longshotgene why did you specifically mention the gateways? why would the valli there be any different then the rest of the wall? Quote Link to comment Share on other sites More sharing options...
longshotgene Posted February 13, 2009 Author Report Share Posted February 13, 2009 To answer your question about the gateways follows: You would have to see photos of it, but the ground upon which Hadrian's Wall is built is very unstable. If you talk to any shepherds in that country, they are constantly re-building their rock fences. Ground shift and constant rainfall leads to plenty of erosion and tumbling of stone. A wall ten feet thick, twenty feet tall places a lot of additional stress upon the ground. When you examine the valli aerially, they look like gigantic drainage downspouts that border the roads leading through the gateways to the major highway on the southern side of the mountain. To see it as a drainage ditch would also explain the need of a vallum on the opposing side of the wall. If it were to have acted as a moat, it would have been filled with water constantly to prevent an assault. The Caledonii to the north did not have siege equipment. They simply went around the wall in times of war. The texture of the ground also does not prove to be conducive to the building of a large scale sewer system. Hadrian Quote Link to comment Share on other sites More sharing options...
caldrail Posted February 13, 2009 Report Share Posted February 13, 2009 Hadrian was taking advantage of a natural escarpment and insisted in certain features, such as a gate every mile even when it opens onto a cliff. The actual terrain wasn't considered by him, and if any Roman engineers mentioned I daresay they got put straight. In other words, they were expected to build the wall as ordered. Actually they didn't, because as we know the scale of the wall reduced during construcion. Some sections of the wall are smaller than the foundations. As a no-go zone... difficult to say. The Wall was a security barrier certainly and the road alongside used by the military for patrols, but then all Roman roads were built for military and adminstration purposes, not civilian use, yet they still travelled on the road without problem. Also, there were Romano-British settlements along the wall which must have communicated with one another? Also, the wall is not a military fortification, but a civil security barrier. The gates were there to allow the public passage through it, a sort of customs barrier in the ancient world so that the locals couldn't smuggle weapons or avoid taxation. Quote Link to comment Share on other sites More sharing options...
Melvadius Posted February 13, 2009 Report Share Posted February 13, 2009 I think there is a bit of confusion in this posting, it is generally agreed that the Vallum is a secondary structure built after the Wall had been completed which runs behind the Wall. As the English Heritage website states it was generally built 50 to 90 metres behind the Wall. It therefore acted to define the rear of the military zone, and as most historians/ archaeologists working on the Wall area now believe was probably intended as a 'customs' barrier controlling movement of people into and out of the the military area c/f images and short text on the English Heritage website at: http://www.english-heritage.org.uk/server/show/nav.1163 In actual fact in at least one instance it was a lot further than 90 metres away. As such it is unlikely that it was intended to make the Wall 'more stable'. Thie probablye 'customs' aspect of the vallum probably was a major issue at the Western end where one of the tribal areas has apparently been cut in half by the route of the Wall - unfortunately it is not recorded what they thought of this but it probably would have been unprintable The ditch in front of the Wall with its accompanying glacis has a more obviously military/defensive use, so in my view could not be considered as primarily to have a stabalising purpose. In point of fact there is recorded evidence for at least one section of the Wall (just west of Segendunum at the eastern end of the Wall) actually collapsing into the defensive ditch while still in use and having to be rebuilt. The Romans did include some small tunnels in the wall to allow the passage of water in streams from one side to the other as well as bridging several more major river barriers along its course. Therefore the Romans did take some account of the issues of water but probably not in the way suggested. Melvadius Quote Link to comment Share on other sites More sharing options...
Northern Neil Posted February 13, 2009 Report Share Posted February 13, 2009 I think we need to dispense utterly with the word 'moat' when referring to Roman stuctures. A moat was a typicallly medieval feature, which whilst containing water, was actually very rare (more common in Hollywood movies). Imagine the work needed to keep water in a moat - lining it with clay, preventing leaks and marsh developing either side. Feasible with a small medieval castle, not so feasible over 80 miles of vastly undulating terrain. Medieval moated castles in England are typically rare and late period; the only examples I can think of (Bodiam and Scotney, Southern England) it apears that the moat was as much for aesthetic properties as defensive - and partly formed from a natural pond. All Roman and most medieval defensive ditches were dry and their function was to provide an obstacle to anyone trying to cross a rampart. That said, there is no reason why Longshotgene's sugestion that they performed drainage functions shouldn't at least be partially true. Whilst primarily there for defensive reasons, I have seen parts of the wall where a small drainage culvert empties directly into the defensive ditch. I can imagine a defensive ditch with a foot or so of prurient mud in the bottom to be quite a deterrent! Quote Link to comment Share on other sites More sharing options...
caldrail Posted February 13, 2009 Report Share Posted February 13, 2009 I think there is a bit of confusion in this posting, it is generally agreed that the Vallum is a secondary structure built after the Wall had been completed which runs behind the Wall. It is worth emphasising. I'm not confused however, I just consider the wall, the parallel road, and the vallae as part of the same system, a controlled frontier with politically unstable territory either side. Quote Link to comment Share on other sites More sharing options...
Melvadius Posted February 13, 2009 Report Share Posted February 13, 2009 I think there is a bit of confusion in this posting, it is generally agreed that the Vallum is a secondary structure built after the Wall had been completed which runs behind the Wall. It is worth emphasising. I'm not confused however, I just consider the wall, the parallel road, and the vallae as part of the same system, a controlled frontier with politically unstable territory either side. As you will have seen from my original posting I have no arguments about the Wall being part of a complex frontier system. My comments were more about some of the other ideas which have been suggested. I have visited the Wall area several times and also done some drystone walling in my time. I have to say that it is pretty typical upland moorland so yes local farmers need to maintain their drystone walls (drystone dykes in Scotland) but that is a normal feature of such unmortared walls and routine maintenance simply means that normally all they have to do is tap back into place any loose stones once or twice a year. By doing that, unless in exceptionally difficult circumstances, drystone walls have been known to stand for 50 or even 300 years without needing a major rebuilding. Major rebuilding normally is a result of routine maintenance not being carried out for several years rather than due to what seems fairly standard upland soggy ground conditions. Melvadius Quote Link to comment Share on other sites More sharing options...
CiceroD Posted February 13, 2009 Report Share Posted February 13, 2009 (edited) To answer your question about the gateways follows: You would have to see photos of it, but the ground upon which Hadrian's Wall is built is very unstable. If you talk to any shepherds in that country, they are constantly re-building their rock fences. Ground shift and constant rainfall leads to plenty of erosion and tumbling of stone. Where did you hear this? Is the ground unstable because of smectite clay (which expands and contracts with moisture). Or is it simply a matter of erosion? Besides, I'm sure that a defensive wall would have a far more substantial foundation then farmer's stone fences. Edited February 16, 2009 by CiceroD Quote Link to comment Share on other sites More sharing options...
Melvadius Posted February 14, 2009 Report Share Posted February 14, 2009 Hadrian's Wall wouldn't have spread much impervious surface over the land. As I understand it they wouldn't have had many problems with erosion undermining their wall as long as the foundation was sound. An exception would have happened if/when the wall would cross a stream. They would have to put in culverts or some similar measure. Are there any examples of this? The short answer is yes. Hadrian's Wall immediately to the east of Housteads fort runs down to a hollow only bout 50-100 yards along the Wall line where it crosses the course of a small stream. The Romans built a small culvert into the base of the Wall at this point. I have a photograph of it somewhere about the house so if I find it I will post it onto the gallery when I next get the chance. Melvadius Quote Link to comment Share on other sites More sharing options...
longshotgene Posted February 16, 2009 Author Report Share Posted February 16, 2009 I just read in a text this weekend that there were gates at the vallum. Now I don't know about you guys, but the vallum is not that tall. Did the Romans have a running palisade on top of it? I have read several texts and cannot find anything about a palisade on top of the vallum. If there were gates directly in line with the mile castles, there would almost have to have been a palisade of some sort. The vallum is not tall enough to keep people out. As far as the composition of the land, I am not too sure. I never did soil sampling. I do know from my excavation work at the forts some mile or two from the wall that there is a great deal of topsoil and then clay. The wall was constructed from dry stone on the facade, but the interior is constructed of loose rubble mixed with concrete. That would void the dry wall argument. The reason the majority of the wall is not standing today is because almost every house along the wall possesses several pieces of the exterior. I saw people carving on the wall to get a piece of it when I was there. Everyone wants a souvenir. Quote Link to comment Share on other sites More sharing options...
Melvadius Posted February 17, 2009 Report Share Posted February 17, 2009 I Quote Link to comment Share on other sites More sharing options...
longshotgene Posted February 17, 2009 Author Report Share Posted February 17, 2009 I understand what you're saying, but why have a three foot tall mound of dirt with gates placed so far along at certain intervals? That would be like placing a framed door in the middle of a field without any accompanying wall to connect to. They are finding the foundational remains of timbers in the stratum in the United States at certain archaeological sites. Why it would seem ludicrous to have had timbers or some sort of wall connecting these gates before allowing someone to enter upon the main wall? The vallum had to have served some purpose other than being a mound of dirt that acted as a boundary. By building the mound, you would allow proper drainage. By allowing proper drainage, you would help prohibit the risk of rotting on the palisade structure. The vallum had to serve some sort of purpose other than being a mound of dirt. If this is not the case, the only other thing I could see the vallum as being, is a leftover feature from the days of Agricola when he pushed his domain to that far extent. By the time Hadrian got there, the vallum was merely carved up to allow people to pass through at the various checkpoints. After all, this is what Hadrian did in Germania superior and inferior. He created new fortifications in place of the old. Quote Link to comment Share on other sites More sharing options...
Northern Neil Posted February 17, 2009 Report Share Posted February 17, 2009 Hadrian's wall controlled and taxed trade as well as military threats. Try taking a horse and cart over the vallum mounds and ditch. Pallisade or not, it would be impossible to scale. Quote Link to comment Share on other sites More sharing options...
longshotgene Posted February 17, 2009 Author Report Share Posted February 17, 2009 I disagree. I have walked the wall in depth and studied extensive parts of the remains of the vallum. Cart, yes, it may be a little difficult. As far as a horse, it would be easy to traverse the vallum. The Caledonians mostly would have been on foot, which would have proved far more suitable for crossing the vallum. I just don't see a giant mound of dirt as being an effective deterrent without some further measure. Something else had to have been there at one time. Even if Agricola had built the vallum as an early means of defense, it had to have had something else on it. Sheep cross it every day as they graze. Either it has been worn down, or it is not even a fragment of its once glory. Quote Link to comment Share on other sites More sharing options...
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