The news of this week I decided to publish it before yesterday (although the information and had prepared for weeks), because that day was carried out advocacy work EOG Naval Engineering EPS of Ferrol and a new group of graduates began his new professional journey. Take this opportunity to congratulate the three graduates and graduates who were tutored by me, are Paula Cartell, Godin and Jesus Guzman Leticia. And note that among others also graduated which was a brilliant student of mine, the Lucene Elisa Fernández Marcelina Uriarte, that was rated honors, with an original work that studies the behavior of passage in cases of abandoning ship. And it was in defense of that work, in which I was present, in which the name of several sunken vessels mentioned, and among them that gives life to the story to which I will refer today. Although the name of the ship that will speak to any of you can remember to do it shattered the bridge of "The Pious" of Ferrol in January 1998 (the rig "Discoverer Enterprise"), this is a different case, Spain and less known.
On Friday 6 March 1987, the "Herald of Free Enterprise" he had "changed the guard": another ship had been decommissioned and, that day, I had to make the Dover-Zeebrugge route instead of the usual Dover-Calais. For a less specialized ship the thing had not had another significance to navigate a little more (two hours) but, differentiates it from Dover to Calais, Zeebrugge terminal did not allow the "Herald" operate simultaneously with both covers and ro-ro, also, posed problems tide place the ramp Cover E, so he had to produce a four-foot seat aproante burdening two tanks to work at high tide in the afternoon.
A "ro-ro" is a typical vessel with a flush deck from bow to stern (ro-ro deck) located a few meters above the waterline and aft ends in a ramp for embarking and disembarking vehicles, largely "trailers" without own tractor. Like any shipment of vehicles crammed much earlier in volume by weight.
The ro-ros certain size usually have two or more decks interconnected by ramps, but the common feature is the absence of compartmentalization in cargo spaces. Under the ro-ro deck ballast tanks are located, fuel and engine room, al lack of vertical dimension, is particularly vulnerable to floods or various humaredas.
Above the cargo deck is situated bridge and, if it is a pure freighter, a crew accommodation.
The ideal environment for these ships is a narrow (Tangiers-Cadiz) or archipelago near the mainland (Cadiz-Las Palmas), and transport demand covering shipments are those for valuable, urgent or perishable compensates get into a truck and save handling in transit. If demand includes private cars with their occupants (Algeciras-Ceuta) known "ro-ro ferry" appears to, despite appearances, in essence is nothing more than a ro-ro café. However, that I was on board the "John J. Sister "by Trasmediterránea, I have to say that ship had many more improvements cafeteria (dining, swimming pool, disco, etc.).
Twenty years ago, Ferry routes the Channel were dominated by two state-owned companies and other private (la británica Townsend Thoresen). This company received 1980 German shipyards Schichau Unterweser three very specialized units, well set a record size, were constructed to measure line Dover-Calais. They were few vessels 132 meters in length, 22,7 Sleeve, 7.950 TRB, ability to 1.300 Passengers and 350 vehicles, doors fore and aft and two ro-ro decks, each with its own ramp forward.
Around 17:00 It began shipping the passage for the return trip to Dover. They also embarked a hundred British servicemen stationed in Germany on their way to enjoy their permissions, many with car and family; Total boarded 459 passengers, but only a hundred of them with nominal tickets. After parking their 81 private vehicles on ro-ro decks, the passage was settling by the broad public premises Covers B and C (the usual mix of cafe and lounge) while, down, three other buses were loaded and forty seven heavy trailers that, to enter the last, if the bow estibaron.
On arrival in Zeebrugge, Second Bosun Mark Stanley opened the bow ramp to allow unloading vehicles and then oversaw cleaning and maintenance until, with vehicles already on board for Dover and ship out, was relieved by the Boatswain Terence Ayling; Stanley then went to his cabin, and he got into his bunk. About how and why such relief there are several versions, the most plausible (a transcript of the official report) puts to the 1810 h, and in "harbor stations" and full output maneuver, which had begun to 1805 h. Stanley was responsible for closing the ramps bow before leaving port and the first Official Leslie Sabel verify that indeed were closed but, for lo visto, was also common encontrárselas already closed for having done any sailor walked by.
Then, the ferry and had to be happening inside the harbor breakwater and just four points ahead 12 knots. At 1823 h left behind outside breakwater, Captain Lewry ordered six points ahead three axes (a regime 18 knots) and the "Herald" faced the North Sea a hole the size of an apartment (thirty square meters) and adjacent a flush deck.
But maritime disasters do not usually occur without further, but as a result of several previous disasters intertwined. In the case of the "Herald" We could start with the modern design of the bow ramp, instead of opening sideways and upward slid horizontally preventing, in the absence of other system, It could be seen from the bridge if they were open. Yet things could have come to nothing arrival at Dover because, with dead calm, the bow wave should not go through the ramp. But a couple of things that made the difference between dismissal and previous. Around 1740 h once the loading of vehicles had begun ballasting tanks bow, but forty three minutes later and longer with tips, the ship was still three feet trim-, just enough to let some water throughout avante but not enough for the sinking originarle. A sail trim-added effect is that after a certain speed, adversely affects the maneuverability of the vessel, and may that that was the straw that broke the camel.
At the time the CC. Guitart riola and calculated that, to exit the channel at a speed of 16 to 20 knots, subsequent "squat effect" to reduce probes increased the vessel's draft between 1,3 and 1,9 meters. And so, to 1825 h (two minutes after the Captain Lewry ordered six points ahead), drop that was to fill the glass broke into the G Deck as a stream whose initial rate would be around three tons per second; without bulkheads containing, the flood ran from bow to stern and port to starboard. Given the problems mentioned maneuvering, be assumed that the rudder would be working wrong and know that they had not yet taken the side stabilizers (fins) so that, in less than one minute, the water was a band and the ship heeled over about thirty degrees to port. The more water coming over the bow and sinking was the most caudal, while the "Herald" was sailing over 15 knots; forty seconds later, after a sharp drop lucky and starboard that definitely out of the channel, el buque Zozobra; clocks stopped at bridge 1828 h. The ferry remained a media mile NW of the mouth, heeled ninety-five degrees to port and its side resting on the bottom in about eleven meters probes, half sleeve so it was out of water.
Most of the passengers were in the cafe and public places of the C Cover, I seeing thrown against the windows port through a land slide suddenly become. Seconds later, the cafe was a bottomless pool of water ice whose edge (starboard windows) I was about seven feet above the water surface.
Luckily, NATO warships were conducting maneuvers in the area and, soon, a British helicopter deposited on the "Herald" a couple of divers who managed to rescue alive a third of the hundreds of people still trapped in the cafeteria. Since the accident happened on a very busy port area and virtually, the rescue operation was immediate and massive, the participating naval units, thirty-nine civilian ships helicopters placed on board a total of nineteen Belgian and British divers, but time playing against. In March the temperature of the North Sea is about six degrees, fifteen minutes to spare a good swimmer rendered inoperable by hypothermia and fifteen others may be enough to kill him. After two and a half hours was unreasonable to expect rescue from water bodies other than.
A hundred eighty-eight people died in this wreck, the most serious peacetime British shipping from the loss of the "Titanic".
The conclusions were clear and, while recognizing the obvious negligence on the part of the envelope, he lambasted the organization of the shipping in unusual terms. For example, It proved that due to the workload, in the "Herald" three different endowments junior overlapped five other officers, preventing develop a real team and that, but in five months came to pass by the "Herald" fifty-six official (It was kind of a training ship), on his last trip took one for less. Such detail would explain the position of first officer demanded superhuman qualities to load vehicles against the clock and supernatural qualities to be in two places at once.
It was mentioned that, at least five previous occasions, other ships of the company were already out to sea with a ramp without closing and that one of the twins "Herald" came several hours sailing with open bow. When, in 1983, ship forgot to close both the bow and the stern, asked one of the captains of the shipping installation in bridge status lights and gates.
If the "Herald" trim-left port was needed because the existing pump ninety minutes to complete the shedding and, though Captain Lewry himself had informed his superiors of the problem six months ago (and two other captains before him), delay was unreasonable hour and a half out to sea several times a day because the ship badly governed.
In January 1977 the International Maritime Organization (IMO) published a study on the controversial security ro-ros showing that, although losses RoRo ferries were similar to those of other ships (2.3 per thousand), of the 4.584 killed in maritime accidents between 1989 and 1994, 1.544 had perished aboard a ferry, one third of the share despite being much smaller ferry. As illustrative, the data might not mean anything but, usually, aboard a ferry traveling many more people remaining aboard merchant and, for the same reason, un Boeing 747 is not necessarily more dangerous than a balloon. Instead, Another study on the basis of 341 accidents on ro-ros of all kinds between 1965 and 1982 and submitted to the IMO by the classification was more significant Norske Veritas: although the percentage of ro-ros lost during that period was the only 0.25% against a 0.55% the total merchant fleet, the 43% of ro-ros were lost due to problems related to the charges at an 16% in the rest of the fleet and the 25% by collision with an equivalent number of 9%. The problem was defined as it was found that over 70% of ro-ros lost in collisions had occurred loss of life and, in the 60% cases, the ship had capsized or sunk in less than ten minutes. Evidently, the problem of the ro-ros resides in a much lower resistance than other failures better compartmented vessels, not be surprising corollary of the IMO: “…ro-ros are highly sophisticated ships which require very careful handling. This makes them exceptionally vulnerable to human error”. And open ramps, clear.
A year after the loss of "Herald" and with a few hard-learned lessons, IMO began issuing the highest safety measures for ro-ro ferries, as the obligation to install position indicators gates on the bridge, Inlet water detectors in the cargo deck, emergency lighting autonomy to three hours in public spaces, draft indicators when it is not visible from the outside or demanding specifications for residual stability after flooding.
DEFINITION OF THE PHENOMENON SQUAT
The phenomenon of increase in draft and trim on ships sailing through narrow channels and shallow water, and waves generated by these is a known fact, especially in the case of fast ships.
A clear and simple way to define the "squat" is: change in draft and trim of a ship which occurs as a result of changes in hydrodynamic pressure on the hull, in their movement in water of any depth.
The phenomenon was initially justified by the narrowing of the liquid vein in the presence of the hull, according to the Law of Bernouilli.
In other words when a ship is in shallow and / or restricted changes of the pressure forces on the hull causing a dynamic change increase draft and trim on the hull, depending on the geometric characteristics of the vessel and the profile of the navigation area in depth and width and speed of traffic.
A year after the loss of the Herald and 188 human lives in the Channel, IMO began to enact more stringent prevention measures for ro-ro ferries. The SOLAS convention was amended again after the Estonia disaster in the Baltic, over 900 dead.