Construction was according to a plan by Richard Steel, an engineer from the King's headquarters in Oxford.
[2] Although there is no definite description of the fort, similar structures consisted of four earthen bastions surrounded by a ditch.
Accommodation and catering facilities were contained in tented constructions in the middle of the enclosure.
Parliamentary forces moved canons into position on the eastern side of the Pill in addition to those on ships in the Haven, and a bombardment of the fort began.
[2] It was manned by Parliamentarian forces for the remainder of the conflict, and dismantled prior to the outbreak of the Second Civil War in 1648.