No official information at present. The following observed from plans in Roman Camps in England (fig.146 p.179)
This fort lies just 50 metres outside the south-east corner of the civil settlement of Pennocrucium, in the junction formed by the Watling Street with the road south to Greensforge to the east, about 50m (c.160ft) south of Watling Street and parallel with it. It's shape is a perfect parallelogram, almost square, with all sides measuring about 150m (c.490ft), covering an area of 2.2 ha (5½ acres) and aligned east-west. The fort was defended by a double-ditch system on all sides, but no entrances are apparent on AP's.
This enclosure may have been large enough to house cohors [peditata] milliaria, a one-thousand strong infantry unit such as Cohors I Tungrorum, but this type of regiment is fairly rare and none can be confirmed in Britain until the close of the first century. Alternately, the fort is easily large enough to have housed a cohors equitata quingenaria, a five-hundred strong mixed unit of both infantry and cavalry which would have been an ideal unit to garrison the area, the infantry detachment set to guard the crossing of the Penk and the cavalry squadron to patrol the Watling Street to east and west.