TAC 35 Index
Abberley Hill in Worcestershire and Milk Hill in Wiltshire were promoted to Marilyns in Alan Dawson's 1997 update. (See also TAC32, p3.) In each case, the status is critically dependent on railway cuttings at the cols separating them from higher ground. That is to say, the drop from their summits to the "natural" (pre-1800) cols is less than 150m, whereas the drop to the track level in the cutting may be more than that figure.
I suggest that neither of these hills should in fact qualify. I have two reasons, one conceptual and the other practical. On the former, it does not seem satisfactory to exclude from consideration things such as masts, buildings, and bridges, while allowing cuttings (presumably rail and road cuttings would both have to be allowed?) to influence the level of the col. It would be more consistent, in my view, to exclude all artificial constructions for this purpose. Now of course many hills have tumuli, ancient hill forts, and so on at the top, and in such cases it may be impossible to locate, or determine the exact height of, the "natural" summit. However, I think it would be more logical to say that "artificial" means "AD" (or, if you prefer, after 1000 or 1500 AD), rather than try to distinguish between some nineteenth- and twentieth-century developments and others.
There is another factor too. In both cases, there was an existing road across the col at the natural level. The railway engineers naturally maintained this link by building a road bridge across their new line. It seems to me that for all practical purposes that means that the height of the col was not changed by the coming of the railway. Otherwise one would have to say, suppose, that the drop of Ben Nevis from continental Europe increased from 1344m to more than 1400m when the Channel Tunnel was opened! Now I do not suggest that if an island with a 155m Marilyn were joined to the mainland by a 10m-high bridge then the hill should become a SubMarilyn. But there does seem to be a difference between a new bridge and one which merely retains the status quo.
The practical reasons are, if anything, even more com-pelling. TAC32 reported that the col relevant to Abberley Hill has been filled in, and its drop is now 145m or so. (I have confirmed the observation, but have not been able to establish the reason. I surmise that the road bridge became unsafe and, as the railway had long been closed, it was cheaper to fill in the col than rebuild the bridge.) So far as Milk Hill is concerned, I have carried out extensive surveys in the region of the col at Bruce Tunnel (a tunnel on the Kennet and Avon Canal), which separates it from higher ground at Walbury Hill. There are some inconsistencies on the OS maps, even at the 1:10000 scale; however, I have concluded that the track level is 148m, and the drop of Milk Hill to the track is 147m, both with an error of 1m or less. This conclusion leaves only one minor anomaly on the maps, whereas any lower track height would lead to several more serious problems. Thus even if the railway cutting is regarded as defining the true height of the col, Milk Hill is only a SubMarilyn - a sad outcome, for it is in a splendid part of the country; but unavoidable nonetheless.
We thus arrive at an intriguing conclusion. Cuttings should not be taken into account when determining Marilyn status - but, even if they were, there are no hills which are thereby enabled to qualify. The argument can therefore become entirely philosophical, unencumbered by actual facts, which makes it far more satisfying!
Ed. - Alan Blanco will respond to these points in TAC36, as part of his annual Marilyn-changes update. We discussed the ins and outs of the status of these two hills back in the spring, whilst climbing the steep hillside above Alva on one of the first really warm days of the year. At the time, various subtle and complex points were made, both for and against inclusion, but needless to say most of these now elude me. There was discussion, however, of the concept of "intent" with regard to summit structures (and col anti-structures such as cuttings). Clearly if someone builds a big cairn on a hilltop to make it higher - as with Ben Lawers many years ago - than this should not count towards the true height. Similarly, if someone dug an opencast cutting through a col with the deliberate aim of deepening that col and thus qualifying a neighbouring hill for some list or other, then that should not count either. (I know this is unlikely/absurd, but, as David says, we are in the realms of philosophy here.) In the case of these actual cuttings, neither were dug with any thought to the height/drop of a hill (unless some extremely devious nineteenth-century list-tinkerer inveigled his or her way on to the local planning boards). Hence it could be argued that there is no "intent" here, any more than if, say, a flash flood (or a meteor strike or a big plane crash as per Lockerbie) carved out a chunk of land and thus deepened the "natural" level of the col. These examples would, surely, be deemed to have deepened the col, just as recent rockfalls on Mount Cook in New Zealand have assuredly decreased its height from the long held 12345ft. Likewise for volcanic activity. That these overseas examples do not undermine (pun intended) David's 1000AD rule is simply because such traumatic geomorphology is unlikely in Britain. But not impossible: what if the Gendarme which toppled from the West Ridge of Gillean around a decade ago had been situated on the col for Am Basteir, where the dip could have been deepened? Height/drop change via frost damage is not impossible in Britain. I think what I'm saying here - and I'm really just thinking aloud - is that, yes, it does look like Abberley and Milk should return to Subdom. But precisely defining inclusion/exclusion parameters is nigh on imposs-ible, even in such a tight listing as the Marilyns. My own "intent" argument, for example, is immediately semi-scuppered by the fact that summit aerials etc are likewise "unintended", yet should still not count towards the height. It's not easy. Anyone else have any thoughts on all this?
TAC 35 Index