A simple reckoning: the giant container ship could not help but get stuck in the Suez Canal

A simple reckoning: the giant container ship could not help but get stuck in the Suez Canal
29 March , 11:58Technology
A woman in her 60s, a former mechanical engineer and expert of the Chamber of Commerce and Industry from the city of Artyom, Primorsky Krai, put forward the simplest and most understandable version of why the container ship Evergrinn got stuck in the Suez Canal. Yes, he just could not help but run into the shore!

"I am already over 60. Specialty - mechanical engineer. By assignment, I worked at a factory, then graduated from graduate school and taught at the graduating department of the Polytechnic Institute", - blogger gull_25 writes about himself , adding that she was quite often ordered to examine baby carriages, for which it is important to calculate deviations. As it turned out, the same technique applies to the giant ship.

Initial data:

one. Suez Canal. The width of the canal is 120 m. However, Wikipedia says that there are sections 150 m wide. But the container ship did not reach this width. The channel is 22 m deep and its edges are not perpendicular to the bottom. Bottom width 40 m.

2. Container ship. Length 400 m, width 59 m, draft 14 m.

The upper right corner shows how this whopper is placed in the channel. It is enough for the container ship to deviate from the course by 10 ° and that's it - it gets stuck! Exactly on the course only trains and trams go - there the rails keep the course. But even in these pieces of iron there are vibrations - they are caused by clearances in the wheelsets. These fluctuations are small. Airplanes, automobiles, sea and river vessels prowl around the course. Instruments and drivers, pilots, navigators monitor its observance.

Below is a diagram of the ship's steering gear. Let's not torment ourselves with showdowns. When the navigator turns the steering wheel, the rudder blade turns through the system of mechanisms. The weak points in the steering mechanism are the feather and stock. Due to their wear during the movement of the vessel, errors of 2 to 4 degrees arise. If, when turning the steering wheel, the deviation exceeds 5 degrees, then the ship can enter the port only with the permission of the Harbor Master, and into the channel - with the permission of the service serving the channel. There was information that before entering the canal, the ship's captain reported to the owner about some problems. Nevertheless, the vessel was admitted, which means that the taxiing error is less than 5 degrees.

Steering device: 1 - rudder blade; 2 - flange connection; 3 - stock; 4 - steering drive; 5 - steering gear; 6 - steering gear; 7 - hand wheel; 8 - ruder post; 9 - helmport tube; 10 - sternpost heel.

But this is with the ideal transmission of the movement of the steering wheel to the steering mechanism. We found out that the taxiing process itself has an error due to the deformations of the assemblies and their wear. This characteristic is checked before each departure of the vessel to the sea.

The error of measuring devices should be 4-10 times more accurate than the measured value. We remember that the axiometer on the rudder has an error of ± 1 °, which means that the steering error will be at least ± 4 °. All these errors were left to the navigator! Of the allowed 10 °, it only has 5 ° to hold the container ship in the center of the channel.

But there is no need to rejoice at these unfortunate 5 °. The container ship does not stand still, but goes along the canal. The rate at which the steering is activated (sailors say "rudder shifts") is 28-30 seconds. And where will the container ship go in these half a minute?

But that's not all. If we look at the channel from above, we will see that it is not straight, there are bends, and these are additional restrictions for taxiing, although the map shows that in places of bends the channel has a large width.

So, the container could get stuck for two reasons:

- the steering control was faulty or had steering errors above the permissible limits;

- the navigator did not cope with such a jewelry taxiing of his whopper in a narrow channel.

Even if the ill-fated container ship is taken aground, it will get stuck again. Maybe the channel management service should learn to calculate the risks and not let such giants into the channel?

Original material - in M Yves Journal.

Meanwhile, the head of the administration of the Suez Canal, Osama Rabea, reported that ten tugboats are trying to remove the vessel from the shallows. He noted that the situation is complicated by the size of the vessel and the number of containers on it. According to him, the number of ships awaiting passage through the canal has reached 321.

Container ship Ever Given under the Panama flag completely run aground in the south of the Suez Canal on March 23, blocking traffic. The Japanese company Shohei Kisen, the ship's operator, claims that strong winds were the reason.

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