I suggest that when you use the jib in this way, it's as much to ensure that she pays off on the tack that you want, as to gather stern way. All boats will gather some stern way, given time, and all junk rigged boats will have quite a strong tendency to pay off quickly, as the windage is well forward (make sure that the sheet is very slack, so that the sail doesn't drive before you want it to). It's just that if you need her to pay off on the "right" tack, you'd better hold the sail out on the other side temporarily ( if the sail is small enough that you have the physical strength to do it). Alternatively, as most boats will range to and fro on their mooring, even if just a little, you can just pick the moment to let go so that she will pay off in the direction you want. In general, though, the absence of jib for manoeuvring is not really much of an issue, and it's much easier to use the junk sail's sheet as a "throttle" than with those of bermudan/marconi rigs.

Hoist the sail to a height appropriate to the wind strength. Push the sail (main on a Sloop or aft sail on a split rig) To weather on the opposite side to which you want the stern to go. The stern will pay off in the opposite direction to which the boom is pushed If the stern goes too far push the sail the opposite way. In this way you can steer the boat backwards as far as you want into clear water without use of the rudder. Once clear, push the sail hard in the opposite direction from the direction you want the stern to go, to position yourself in the direction you wish to go forward. Once you have reached the correct angle let go the boom and haul in the sheet until the sail draws and sail away. On split rigs let the front sail feather as you go backwards and sheet in once you are headed in the direction you want to go, usually before you sheet in the aft sail. All very simple and no stress as the sails will never take control unless the sheets get jammed and will not pay out!

Frank,

my first boats (Bermuda sloops) lived on a mooring, and since none of them were more than two tons, I just hoisted the mainsail and then, instead of just casting off the mooring line, I ‘walked it back’ along one side, with the boat turning to the opposite direction (and gaining a bit momentum as well). Then I let the line go and rushed back to the tiller to sail us free from the other boats. Out in free water, the jib was hoisted.

With a sloop JR I guess I would use the same method, except for not needing to hoist any jib.

Arne