1917 OS Map of Palmer’s Shipyard. See the entrance to the shipyard above the lettering Ellison Place,
then the engineering shed immediately to the left of the entrance. Note top from L to R: (i) 420ft graving dock (dry dock). (ii) tidal inlet (HWMOT) used to launch ships from the shipyard containing temporary slipways & scaffolding. (iii) 600ft slipway for ship repair. See discussion.
Click on these links for comparisons : c1960(i), c1960(ii), 1887, 1966, c1968, 2007(i), 2007(ii).
Also see the full wide 1900 view & labels here.

Image of 1917 OS Map of Palmer’s Shipyard.