As explained before we call at Rosyth for Edinburgh. You can also use Leith for that purpose or South Queens Ferry. Leith is tide and wind depended as you have to go through a lock and South Queens Ferry is an anchoring area so my vote goes to Rosyth at all times. Leith is great if you can make it inside the lock but that is very weather dependent. Thus Rosyth it is and there we went. Pilot at 0600 and sailing up through the estuary of the river Forth, called the Firth of Forth towards the dock. We were going against the end of the ebb tide and we noticed about a two-knot current running, easing off all the time, and not much taking into account what we would have on departure. Before we come to the berth we have to pass under the Forth Railway Bridge and the Forth Motorway Bridge and those bridges can be an obstacle when the tide is too high. The top of our radar mast reaches a maximum of 46.5 meters above water and that worries pilots if the tide is higher than expected or taking longer to fall than expected. During our last call, the pilot had those concerns, as he was not certain if his calculation was in synch with reality. To avoid a similar situation again I had the mast lowered in the morning, reducing our height to 39.5 meters and that made everybody happy. It is one of the reasons that the Prinsendam can go to Rosyth while the other HAL ships have to drop the hook at South Queen Ferry. The Prinsendam is simply designed for this sort of stuff.
The weather forecast was right this time and we sailed with nearly wind still weather towards the dock, which is not a very exciting affair as it is mainly a cargo dock with no cruise terminal in sight. Still it works for our purposes and they do have a nice shore gangway to hook into the ship. My worries were already about departure. The coming days will bring spring tide and that means that high water is higher, lower water is lower than normal and in order to get from the one to the other, the currents are much stronger. At departure time there would be at least 4 to 5 knots of ebb running, on a 90-degree angle in relation to our port exit course. While that current would be pushing us to the rocks (e.g. the pillar of the motorway bridge) the ship would have to make a 90o turn and end up in the centre of the bridge span, to pass safely under it. To make that manoeuvre in a safe way there were a lot of if’s and when’s to iron out, before I was convinced that the ship would be under control at all times and a 100% safely execution of the manoeuvre could be assured.
Step one, is always to see if there is a Plan B. Can I do this on my own engines and steering? Yes, but if at the crucial moment we would not have enough speed the ship might not turn fast enough yet. Solution; hook up a strong tugboat that can give help by increasing the rate with which we are turning if needed. Is there enough room to turn while we are being set towards the rocks? Barely, but if we go a bit up river first and swing there, then it will be a lot easier. Thus with a long Master – Pilot conference we trashed out the whole plan. Staying longer and waiting for less current was not really an option, as that would cost too much time for our journey to Tilbury.
Thus with that in our minds we left and under the watchful eye of the local longshoremen we carried out our plan. The latter knew that there might be some excitement coming when a ship sails at the full Ebb current, so they were happily waiting “further developments”. Those developments did not come as we had all our margins properly set, but it was interesting to see that while we made the turn with 8 knots, we were set away with 4 knots, which is 50% of the ships speed. Faster is not possible as otherwise you overshoot the turn and do not end up under the centre of the bridge. The tugboat hung as a fail safe at the stern but the Pilot made the perfect turn while I ensured that he had the absolute constant speed to do it. When a ship turns it looses speed and when you plan a constant rate in course change you need a constant speed to do that. With a turn based on 8 knots speed and 4 knots current, the whole picture suddenly changes if that 8 knots speed becomes 6 knots.
Once lined up we were flushed down the river with those four knots, although it became two when we came into the wider area of the Firth of forth. Tomorrow we will be at sea, sailing down the East Coast of England, and guess what,…………..it is going to blow again.