Causes of the disaster MS Herald of Free Enterprise in 1987

[Hydro]

Typically, the causes of man-made disasters are a combination of many factors - technical, psychological, administrative, climatic, etc.

Here I wanted to discuss the causes of the MS Herald of Free Enterprise disaster in 1987 from the point of view, so to speak, of “scientific factors” related to hydrodynamics.
Perhaps I'm wrong and everything written below has nothing to do with this. Then you can move this topic somewhere else or delete it at all.

So, to begin with, you need to watch from this place this video of the investigation of this disaster by the National Geographic Documentary channel - “Seconds from Disaster. Zeebrugge Ferry Disaster”.

(I recommend watching this entire episode from the very beginning)

Also, here are some screenshots from there

So, according to the results of the investigation, one of the physical factors that contributed to the accident was the so-called “squat effect”.

However, I wanted to draw attention to one more factor that, in my opinion, may also be at play.

In this topic a certain hydraulic turbine operating on a certain " hydrodynamic effect."

This effect, according to the authors, is a consequence of the state of fluid flows approaching the so-called “critical state”, determined by the ratio of depth and flow speed.
According to the authors, the effect manifests itself in that when approaching such a flow state, a “power surge” effect occurs.
In my opinion, this may occur in the described case, when the wave in front of the ship rises sharply due to the additional power received in this mode.

I would like to hear the opinion of specialists and marine engineers.

Edited January 8 by Hydro

[Hydro]

Popular science article on the topic.
Some may find it interesting.

[OceanBreeze]

On 1/8/2024 at 2:10 PM, Hydro said:

Typically, the causes of man-made disasters are a combination of many factors - technical, psychological, administrative, climatic, etc.

Here I wanted to discuss the causes of the MS Herald of Free Enterprise disaster in 1987 from the point of view, so to speak, of “scientific factors” related to hydrodynamics.
Perhaps I'm wrong and everything written below has nothing to do with this. Then you can move this topic somewhere else or delete it at all.

So, to begin with, you need to watch from this place this video of the investigation of this disaster by the National Geographic Documentary channel - “Seconds from Disaster. Zeebrugge Ferry Disaster”.

(I recommend watching this entire episode from the very beginning)

 

So, according to the results of the investigation, one of the physical factors that contributed to the accident was the so-called “squat effect”.

However, I wanted to draw attention to one more factor that, in my opinion, may also be at play.

In this topic a certain hydraulic turbine operating on a certain " hydrodynamic effect."

This effect, according to the authors, is a consequence of the state of fluid flows approaching the so-called “critical state”, determined by the ratio of depth and flow speed.
According to the authors, the effect manifests itself in that when approaching such a flow state, a “power surge” effect occurs.
In my opinion, this may occur in the described case, when the wave in front of the ship rises sharply due to the additional power received in this mode.

I would like to hear the opinion of specialists and marine engineers.

While scientific theories involving the squat effect and the dead water phenomenon are interesting, as far as I could determine, the primary cause of MS Herald of Free Enterprise disaster, was the crew left the watertight doors in the bow open, allowing water to rush in, down the length of the vessel causing the ship to list to the port side and sink very quickly.

If you only want to discuss the cause of this disaster, it was human error; no mystery there, and no need to watch any video animations.

If you want to discuss the dead water phenomenon for the sake of having a science discussion, we can try that without reference to the MS Herald of Free Enterprise.

My contribution to this discussion will be very limited for two reasons: I am a marine engineer, not an oceanographer. I just need to know how to avoid these hazards and to recognize them when they occur and what actions to take to escape from them. For a detailed scientific dissertation, we need to get inputs from a physical oceanographer.

Briefly, the dead water phenomenon is important; as it is encountered by ships in all seas and oceans where the waters have different densities due to a mixture either of salinity or temperature. Scientific investigation has revealed two types of drag associated with this dead water phenomenon:

     Nansen wave-making drag, which causes a constant abnormally low speed regardless of engine power.

    Ekman wave-making drag, characterized by speed oscillations in the entangled ship.

The second of these drag effects is amplified when there is a lateral confinement on the ship’s dynamics; as encountered when a ship enters a narrow waterway. By amplifying the height of the waves, lateral confinement intensifies the Ekman wave-making drag. This effect can be studied in a laboratory by constructing a narrow water tank and observing the effect as model boats are pulled through the water.

Nansen wave-making drag affects ship dynamics in the open sea. In the open sea, or a wide channel, there are less Ekman oscillations and, providing the differential density conditions exist, a ship reaches a steady state where the Nansen wave-making drag dominates. Since it is impossible to duplicate the open sea in a laboratory setting, almost no laboratory experiments have been conducted on Nansen wave-making drag.

As I said at the start, the above is a very simplistic introduction. A deeper discussion would be very technical and mathematical, require a lot of effort, and be of no interest to anyone, just my opinion.

 

 

[Hydro]

2 hours ago, OceanBreeze said:

 

While scientific theories involving the squat effect and the dead water phenomenon are interesting, as far as I could determine, the primary cause of MS Herald of Free Enterprise disaster, was the crew left the watertight doors in the bow open, allowing water to rush in, down the length of the vessel causing the ship to list to the port side and sink very quickly.

 

If you only want to discuss the cause of this disaster, it was human error; no mystery there, and no need to watch any video animations.

I called the reason that you said that the crew left the watertight doors in the bow open a “psychological factor.” It is obvious and quite trivial, and has nothing to do with science and technology.
I just wanted to identify all the reasons for the “scientific factors”.

One of them is the “squat effect”, the second one is the “free surface effect” and the third one, as it seems to me, is the “critical depth and speed effect”.
It was this that allowed the wave to rise 4 meters higher and flood the hold.

I think that if it were not for this effect, then neither psychological factors nor the other mentioned “scientific factors” would have played a decisive role.

In that video there is even a comment that once a similar ship also went to sea with the watertight doors open, but no disaster occurred then, since there were no other factors.
I'll try to find this place on video.

I didn't know about the Ekman and Nansen effects.
Thanks, I'll look in the literature.
Don't you think that they have some correlation with the Russell soliton and the Krylov soliton?

Edited January 22 by Hydro

[Hydro]

30 minutes ago, Hydro said:

In that video there is even a comment that once a similar ship also went to sea with the watertight doors open, but no disaster occurred then, since there were no other factors.

I'll try to find this place on video.

Here it is https://youtu.be/mocj_Zdyi6I?t=2010.
A similar ferry left the port of Dover with its doors open, but no disaster occurred.
That is why the investigation into this case was very thorough to identify all possible factors.

[OceanBreeze]

7 hours ago, Hydro said:

I called the reason that you said that the crew left the watertight doors in the bow open a “psychological factor.” It is obvious and quite trivial, and has nothing to do with science and technology.
I just wanted to identify all the reasons for the “scientific factors”.

One of them is the “squat effect”, the second one is the “free surface effect” and the third one, as it seems to me, is the “critical depth and speed effect”.
It was this that allowed the wave to rise 4 meters higher and flood the hold.

I think that if it were not for this effect, then neither psychological factors nor the other mentioned “scientific factors” would have played a decisive role.

 

I don’t have time to be watching videos, but I have read the REPORT OF COURT NO. 8074 FORMAL INVESTIGATION MV HERALD OF FREE ENTERPRISE:

[QUOTE]

DECISION OF THE COURT

The Roll on/Roll off passenger and freight ferry

HERALD OF FREE ENTERPRISE

registered at the port of Dover (O.N.379260)

In the matter of a Formal Investigation held at Church House, Westminster and at Alexandra House, Kingsway, W.C.1. on 29 days between the 27th day of April 1987 and the 12th day of June 1987 before the Honourable Mr. Justice Sheen, . . .into the circumstances attending the capsizing of the Roll on/Roll off passenger ferry H E R A L D OF FREE ENTERPRISE in the approaches to the port of Zeebrugge with the loss of 188 lives on the 6th day of March 1987.

The Court, having carefully inquired into the circumstances attending the above-mentioned shipping casualty, finds, for the reasons stated in the Report, that the capsizing of the H E R A L D OF FREE ENTERPRISE was partly caused or contributed to by serious negligence in the discharge of their duties by Captain David Lewry (Master), Mr. Leslie Sabel (Chief Officer) and Mr. Mark Victor Stanley (Assistant bosun), and partly caused or contributed to by the fault of Townsend Car Ferries Limited (the Owners).

The court suspends the certificate of the said Captain David Lewry for a period of one year from the 24^th July 1987. The Court suspends the certificate of the said Mr. Leslie Sabel for a period of two years from the 24th July 1987.

MV HERALD OF FREE ENTERPRISE

REPORT OF COURT NO. 8074 FORMAL INVESTIGATION

[UNQUOTE]

Nowhere in the report is there any mention of unusual wave phenomena; it is all down to human error.

If the water-tight bow doors were closed, the accident would not have happened.

You may call that “psychological” and “trivial” since it does not involve physics, however the inescapable fact is human error caused this disaster.

That is not my opinion, it is the conclusion reached by the formal investigation:

[QUOTE]

10. The immediate cause of the disaster

10.1 The H E R A L D capsized because she went to sea with her inner and outer bow doors open.

From the outset Mr. Mark Victor Stanley, who was the assistant bosun, has accepted that it was his duty to close the bow doors at the time of departure from Zeebrugge and that he failed to carry out this duty.

[UNQUOTE]

I only saw a passing reference to dynamic sinkage (squat) as well as a mention that the ship may have been making headway too fast, producing waves which went over the bow. The fact remains; If the bow doors were closed, water could have gone halfway up the closed doors and she would not have capsized.

I have no doubt that the ship’s owners, facing many large lawsuits, would have hired some “experts” to concoct a story about naturally occurring phenomena, such as squat and abnormal bow wave height, in the hope of escaping responsibility for this disaster.

 

Quote

In that video there is even a comment that once a similar ship also went to sea with the watertight doors open, but no disaster occurred then, since there were no other factors.
I'll try to find this place on video.

That just shows there is an unacceptable level of negligence among the crews, and they were very fortunate not to have a disaster.
 

Quote

I didn't know about the Ekman and Nansen effects.
Thanks, I'll look in the literature.
Don't you think that they have some correlation with the Russell soliton and the Krylov soliton?

As for the Russell soliton and the Krylov soliton, it seems to me they are similar to the Nansen and Ekman phenomena, but with at least one important difference:  I don’t see any mention of differential water density in the literature on the solitons, although it could be a factor.  I do see where the Krylov soliton occurs in the open sea “over the horizon” so it may be related to the Nansen wave-making drag. The Russel soliton was first reported to happen in a narrow channel, with the boat being towed at constant velocity; that seems very similar to Ekman wave-making drag, but I am just speculating.

This incident to be more suitable as a case study in crew negligence and lack of proper training, rather than a scientific study in oceanography. I am not interested in the former case and not qualified for the latter case so I rest my case.

 

[Hydro]

15 hours ago, OceanBreeze said:

[QUOTE]

10. The immediate cause of the disaster

10.1 The H E R A L D capsized because she went to sea with her inner and outer bow doors open.

 

 

 

 
Well, here we could simply clarify this whole chain of factors

The chain was like this:

The crew did not close the door
The ship accelerated greatly
There was a shalow water on the way
There was a squat effect
There was a critical depth effect
The wave rose above the doors
Water flooded the deck
The ship tilted
There was a free surface effect
It led to a gain of the tilt
The ship lost stability
The ship fell on board

Of course, without the first factor, no subsequent events would have occurred.
Therefore, the court's decision is quite fair.


I think everything is clear here.
But I learned something new from here.