Wall Mile 29 [HB 211–14]
We must now set off down the gently sloping field, the ditch visible to our right, although the curtain wall is still hidden. Crossing a small lane and entering the next field, this time sloping gently upwards, we find a splendid stretch of consolidated curtain wall and ditch at Black Carts. One-third of the way up are the remains of Turret 29a.
Turret 29a (Black Carts) [HB 211–12]
This turret, famously depicted in one of the woodcuts in Collingwood Bruce’s Handbook, survives to eleven courses within its recess, and has the familiar wing walls of a broad-gauge turret wed to the narrow-gauge curtain wall. It was first excavated by John Clayton in 1873 and subsequently re-examined in 1971. The threshold block in the doorway is of particular interest, since it retains the settings for the monolithic uprights that formed the door jambs, and the socket on the eastern side shows which way the door opened (remembering defensive doorways and gateways always opened inwards).
If you are feeling adventurous, you can nip round to the north side of the wall and hunt for a building inscription. One lies 55m from the west end (or 90m from the east) of this stretch of wall and records construction work under a centurion from the first cohort of a legion by the name of Nas(…) Ba(ssus). It has been suggested that legio XX was responsible for the initial construction of this section of wall. Bassus crops up elsewhere and an almost identical stone can be seen in Chesters museum which, although unprovenanced, may well be the pair to this stone. It has long been thought that building inscriptions were only placed on the south face of the curtain wall and that those on the north side were a result of rebuilding work. The fact that this stone is in the second course may give pause to question this argument for their placing, but it may equally hint at a very thorough rebuilding of this bit of the curtain wall (and such major reconstruction work is known elsewhere). Incidentally, since being uncovered, this section of wall has turned from a honey-coloured sandstone to a sooty black, thanks to a rather pervasive black slime. Whilst everybody obsesses about a whitewashed Hadrian’s Wall, I prefer to think of one covered in lichen, slime, and perhaps the odd bit of graffiti.
We cross another lane and continue upwards, along the berm between the curtain wall and ditch. The Military Road is still on the line of the wall, here, and sits on the north mound of the Vallum (where it stays until just after Limestone Corner).
Soon we cross the wall and head west on the south side of it, before crossing back to the north near the trig point (the crossing point varies according to the needs of wear and tear, so keep your eyes peeled for signs). We now follow the line of the ditch, although the actual route of the Trail is not always readily apparent, some walking in the ditch, some not. The wall itself is a low mound to our left near the field wall (which, unusually, does not sit on top of it). Here, the ditch is very shallow, evidently having been little more than marked out, rather than fully excavated. Near the highest point of this section, we reach Milestone 30.
From the air, it is apparent how the wall and ditch change course to take advantage of the slight promontory of Limestone Corner (the Vallum huffily ignores it completely, of course; possibly because it knows there is no limestone here, just whin stone). Why? Because the ditch is then at the edge of the scarp, once again using the lie of the land for tactical advantage.
Milecastle 30 (Limestone Corner) [HB 214–15; haiku]
This milecastle survives as an earthwork to the south of the field wall (which is set back slightly from the line of the curtain wall), excavation showing that the Narrow Wall butted against broad wing walls.