Dear Traddles
Are you sure, that the correct loading position is starbord side at the quay, to load heavy lifts ?
I have sailed as 2nd mate on a containership with all 4 cranes at portside. We always moored with starbordside (opposite side of the cranes), because in this position the cargo could be loaded easier with cranes over the whole ship's beam:
1st No or only small swinging of cranes neccessary
2nd The whole hull of the ship acting as counter weight/gravity against the movement of the cranes.
The cranes had sufficient outreach (30m over the quay) under full weight (32 tonnes each, Gemini 60mt x 2 cranes). Attached you see a picture of the ship.
On oldfashioned heavy lift freighters with their heavy lift derricks in midship's line there was always the problem with the list, as soon as picking up the heavy lift fm the quay.
Now, if the JJ is loading the heavy lift on here starbordside, it seems to be impossible to ballast sufficient at portside to avoid listing to the quay, she will just fall on the quay. I think it is the other way arround to load fm the portside, having the whole ship's body as counter weight/gravity, when picking up the heavy lift fm the quay and if necessary ballasting on the starbord side is more effective to avoid too much list to portside. The derricks are sufficient long to load the heavy lift safely, even with further outreach.
Bgds
ARTSHIP/Horst
Hi BurtonD,
If you look at the attached picture you will see that the bow thruster control is part way over to port and you can see the wake effect from the bow. You will also see that the right hand control for the after (retractable in reality) azipod is angled at 900 and on full speed, this is pushing the ship towards the quay. You can see the wake effect coming from beneath the after crane mounting. With these two controls the ship can be moved physically sideways with great accuracy to position her exactly at the correct place to load her heavy lift cargoes. The thrust from the aft azipod is only effective at very low speeds or if the vessel is stopped. I should point out that when JJ is loading or discharging it is usual for her to go alongside starboard side to the quay. This is because the cranes then have a smaller distance to reach the quay thus enabling the maximum lift to be made. The further out from the base of the crane the hook is, the more the heeling moment on the ship is and the less weight she is able to handle. My picture therefore shows her moving alongside with the wrong side to the quay. Oops
I hope this clears up the matter for you.