Two heavily degraded mushroom-shaped composite wood/iron hatch rollers were recovered from the southern end of the Jacksonville "Blue China" wreck site, 1.5m southeast of the concentration of shell-edged earthenware in Area A. The original cap survives in place on just one example. Each is pierced with a square hole extending along the central axis from the base to the bottom of the cap. BC-05-00403-SF is 22.7cm long and 17.7cm wide at its single preserved end, with a diameter midway down its length of 7.7cm. Its central square shaft is 3.2cm wide and lined with a 0.25cm-thick veneer of iron. Four circular nail holes on the base of the preserved end measure 0.5cm in diameter and are set 3.4cm inward of the outer edge. Circular friction marks caused by repetitive rotation are visible at this end.
Just one end of roller BC-05-00402-SF remains intact and its central barrel and opposite end are heavily degraded. It measures 23.4cm long and has a diameter of 17.6cm at the intact end. The central square shaft running vertically down the middle of the roller is 3.4cm wide with a 0.33cm iron interior lining. The four nails staggered 3.7cm inwards of the base edge each measure 0.8cm in diameter. Concentric friction marks caused by repetitive rotation are again present on the base.
Both hatch rollers originally may have had an iron core or been lined with iron sheet. These objects resemble capstan barrels, but incorporate no obvious holes for capstan bars and have subsequently been identified as hatch rollers (pers. comm. John Broadwater, 1 December 2006). The Oxford Companion to Ships and the Sea (1976: 378) defines such objects used on cargo ships as “pivoted in sections which allow the covers to be rolled back, folding together in cantilever fashion at either end of the hatch opening.