Whoops.....crane barge in Holland goes a bit wrong....

[Pluto]

 

I'm not going to claim to be an expert or even attempt to say what went wrong but I cannot understand why the platform was floating, surely it is normal to use jack up barges.

 

Tim

That does require solid foundations which are unlikely to be found in Holland (I know it is in The Netherlands, but Alphen aan den Rijn is in South Holland). About five years ago I gave a paper on canal conservation in the Castellum Centre, just to the south of the bridge, at the final event of the South Holland year of waterways.

[churchward]

It's quite a catastrophic failure looking online further it looks like several residencies have been effectively destroyed. It seems by the reports that there have been about 20 casualties but thankfully no fatalities and just one person hospitalised with non life threatening injuries. If all that is true it has been a lucky escape looking at the footage and damage done to the houses you would guess some people were buried beneath them. Perhaps everyone was outside, at work, possibly watching the event outside or the authorities had taken the precaution to evacuate those homes before the lift was attempted.

[blackrose]

I maintain the uncontrolled continuing rotation of the far crane was the cause of the disaster. It was obvious the far crane was out of control and rotating inappropriately fast, early in the video. So we must surmise the people on site saw this too and were unable to stop the rotation of the far crane.

 

Therefore the must have been a computer failure that could not be manually countermanded, or a serious health problem for the driver of the far crane.

 

I guess the Dutch can dispense with all the bother of a formal accident enquiry then... Some bloke on a boat in the UK has decided how it happened.

 

I don't understand how it's possible to speak with such certainty about the cause being computer failure or illness just by watching a video?

 

The accident could have been the result of any number of causes or a combination of factors.

Edited August 4, 2015 by blackrose

[Guest]

The rather jolly soundtrack playing in the background seems a little inappropriate.

 

But yes it could be due to a multitude of causes. Clearly somebody realised it was going pear shaped as they can clearly be heard shouting at a point in the video just before it's obvious from the movement of the crane it's going over.

 

It seems incredible to me that anybody could think that was going to be safe, the margin for error looks to be incredibly small, and gob smacking that there wasn't a safety zone implemented around the operation, surely nobody should have been in those apartments?

[magnetman]

 

I guess the Dutch can dispense with all the bother of a formal accident enquiry then... Some bloke on a boat in the UK has decided how it happened.

 

I don't understand how it's possible to speak with such certainty about the cause being computer failure or illness just by watching a video?

 

The accident could have been the result of any number of causes or a combination of factors.

 

It was blatantly the wind which did it

[Guest]

It's quite a catastrophic failure looking online further it looks like several residencies have been effectively destroyed. It seems by the reports that there have been about 20 casualties but thankfully no fatalities and just one person hospitalised with non life threatening injuries. If all that is true it has been a lucky escape looking at the footage and damage done to the houses you would guess some people were buried beneath them. Perhaps everyone was outside, at work, possibly watching the event outside or the authorities had taken the precaution to evacuate those homes before the lift was attempted.

I would hope so.

[Tony Dunkley]

I would think that the bridge deck was going to be dropped into place on a base in the narrows beyond the two pontoons on which the cranes were, and that it had arrived on site on the pontoon with the transport frame on board.

Once lifted clear and slung between the two cranes then both the pontoons (with the cranes) would have been moved into position in the narrows to install the bridge.

During this part of the process I would guess that the load between the two cranes would have been positioned just inboard of the pontoon's deck edges, probably on the multi-axle transporter, for final placement into position.

Everything started going wrong, and the initiating cause of the collapse was, when the crane farthest from the camera slewed very quickly too far left, moving the combined C of G's of both pontoons/cranes and load across the pontoons(s) toward the houses.

It was, therefore, as has been suggested, the rapid, and clearly, unintentional left slewing of the farthest crane that started things going wrong, and the cause of that can only be a control/mechanical malfunction on the crane itself or that the driver was suddenly taken ill during the lift.

Wind speed is monitored before and during any lift, and there is no way that an operation such as this would have gone ahead if the wind was strong enough to present any kind of possible hazard at all.

There is one slightly worrying aspect to this, and that's the pump running, and delivering water overside, on the nearest pontoon. This indicates that there was free surface water in at least one compartment of that pontoon. I wonder if there were others in a similar condition.

Edited August 4, 2015 by Tony Dunkley

[magnetman]

As I see it this was not a lifting operation its was more of a repositioning of the object which initially appears to have two 'legs' resting on the platform barge. One of these legs seemed to move or slide unexpectedly as the weight was taken up which meant that excessive force was placed on the crane further from the camera. the crane operator took steps to counteract this but could not do so resulting on catastrophic failure

 

There would appear to be no reason to lift the object there so they were probably just trying to move it a bit perhaps to stabilise the barge a bit and f123ed it up.

 

 

:speculation:

I have only seen it on a phone screen but the video seems to show a large object (bridge platform?) Suspended by two cranes at a slight angle which means there must have been supports on the platform barge otherwise it would slide. Its one of those supports which has failed I reckon rather than a craneage error.

[Global traveller]

Not sure where all the talk of control/mechanical malfunction and on what basis these are cited as probable cause suddenly appear from, and whilst it may eventually come about that there was a malfunction the most likely cause is poor planning and execution of the operation. Whilst these types of cranes do have a computer within the operators cab, they merely act as an aid to the operator, it is the operator who physically must push the control lever to the left to enable the crane to move to the left and the speed would have been governed by the degree to which the lever is moved and the settings made by the operator to the hydraulic pumps governing the slew (swing). If the operator, as people are surmising, had fallen ill, unless he had collapsed on the control lever forcing it to the left, the lever would have remained in the neutral position and there would have been no movement.

The comments mentioned that the crane slewing left are also incorrect. In this operation the furthest crane from the camera would initially start slewing left whilst the second crane (nearest) would have followed by slewing right, during this operation the bridge deck would have been turned 90degrees in its orientation and would have been touched down on the free space on the deck of the barge. Then as previously mentioned by a previous contributor, the two barges with the cranes on would have been manoeuvred into position between the two bridge abutments and the bridge deck would have been installed.

This whole operation is what in the industry is termed a critical lift and when carried out on dry land with solid foundations it requires experienced crane operators and supervisors; when carried out on floating barges with the additional issues of ballasting and inherent instability, the whole operation becomes a whole lot more riskier and in most cases would be avoided and a different solution sought.

Apologies for the length of the post, if anyone requires further explanations or wishes to discuss further feel free, by the way I have 35 years experience in the Lifting Industry and work for a Dutch lifting and transport company, fortunately not the company involved in this incident.

[Global traveller]

Not sure how to edit my previous post but the line

"The comments mentioned that the crane slewing left are also incorrect"

should have read

"the comments mentioning that the crane slewing left was unintentional either due to malfunction or operator falling ill are also incorrect"

[Tony Dunkley]

Not sure where all the talk of control/mechanical malfunction and on what basis these are cited as probable cause suddenly appear from, and whilst it may eventually come about that there was a malfunction the most likely cause is poor planning and execution of the operation. Whilst these types of cranes do have a computer within the operators cab, they merely act as an aid to the operator, it is the operator who physically must push the control lever to the left to enable the crane to move to the left and the speed would have been governed by the degree to which the lever is moved and the settings made by the operator to the hydraulic pumps governing the slew (swing). If the operator, as people are surmising, had fallen ill, unless he had collapsed on the control lever forcing it to the left, the lever would have remained in the neutral position and there would have been no movement.

The comments mentioned that the crane slewing left are also incorrect. In this operation the furthest crane from the camera would initially start slewing left whilst the second crane (nearest) would have followed by slewing right, during this operation the bridge deck would have been turned 90degrees in its orientation and would have been touched down on the free space on the deck of the barge. Then as previously mentioned by a previous contributor, the two barges with the cranes on would have been manoeuvred into position between the two bridge abutments and the bridge deck would have been installed.

This whole operation is what in the industry is termed a critical lift and when carried out on dry land with solid foundations it requires experienced crane operators and supervisors; when carried out on floating barges with the additional issues of ballasting and inherent instability, the whole operation becomes a whole lot more riskier and in most cases would be avoided and a different solution sought.

Apologies for the length of the post, if anyone requires further explanations or wishes to discuss further feel free, by the way I have 35 years experience in the Lifting Industry and work for a Dutch lifting and transport company, fortunately not the company involved in this incident.

 

I can't agree with your assessment ( in your second para.) of how the operation would have proceeded.

I think the intention was to lay the bridge deck on the multi-axle transporter and, being able to move in any direction horizontally as well as up and down, complete the final positioning using that, and that the cranes would probably have taken no further part.

I don't see why it would be the intention to rotate the bridge deck through 90 degrees because it would then be in the wrong orientation for installing.

Edited August 4, 2015 by Tony Dunkley

[David Mack]

As I see it this was not a lifting operation its was more of a repositioning of the object which initially appears to have two 'legs' resting on the platform barge. One of these legs seemed to move or slide unexpectedly as the weight was taken up which meant that excessive force was placed on the crane further from the camera. the crane operator took steps to counteract this but could not do so resulting on catastrophic failure

 

There would appear to be no reason to lift the object there so they were probably just trying to move it a bit perhaps to stabilise the barge a bit and f123ed it up.

 

 

:speculation:

I have only seen it on a phone screen but the video seems to show a large object (bridge platform?) Suspended by two cranes at a slight angle which means there must have been supports on the platform barge otherwise it would slide. Its one of those supports which has failed I reckon rather than a craneage error.

 

There is a third barge to the left on which the bridge deck started. The two cranes on the pontoon barges lifted it from there. Quite why is not obvious.

[Tony Dunkley]

 

There is a third barge to the left on which the bridge deck started. The two cranes on the pontoon barges lifted it from there. Quite why is not obvious.

 

Because the narrows where the bridge is to be installed won't take two pontoons abreast? . . . . and it would be in the way during the final stages of positioning in any case.

[Global traveller]

I can't agree with your assessment ( in your second para.) of how the operation would have proceeded.

I think the intention was to lay the bridge deck on the multi-axle transporter and, being able to move in any direction horizontally as well as up and down, complete the final positioning using that, and that the cranes would probably have taken no further part.

I don't see why it would be the intention to rotate the bridge deck through 90 degrees because it would be in the wrong orientation for installing.

Tony, the multi axle trailer is purely the trailer that accompanies the crane, bringing the additional ballast and lifting equipment required for the lift. At no point was there any intention to use it during the installation of the bridge deck.

[Arthur Brown]

I think we shall not understand why it failed with any significant accuracy, it's news at the moment but by the time the two cranes are clear there will be no reports in the UK.

 

I still struggle to understand why the lift happened there when there was no obvious "construction site" to receive the bridge section.

[frangar]

I think it would be most interesting to watch how the recovery operation takes place.

 

Cheers

 

Gareth

[magnetman]

I imagine there will be a lot of cutting involved.

[Global traveller]

Tony ref your post #32

 

you are correct in your assumption that the deck was to be installed within the narrows, where the bridge abutments are, you are also correct in that the farthest crane slewed too quickly. What we cannot be clear about at this stage is whether the speed of slewing is due to loss of control of the operation due to the instability of the barge or due to other factors, possibly inexperience of the operator.

Having studied all available footage today in conjunction with our marine engineers, we have identified a few contributing factors which I will not post on a public forum, suffice to say that as per what we have seen this is not an operation we would have signed off as being safe.

A clear indication of the proposed operation can be seen from this promotional video shot just before the incident. https://m.youtube.com/watch?v=hNq2qbf-RY8

[Tony Dunkley]

Tony, the multi axle trailer is purely the trailer that accompanies the crane, bringing the additional ballast and lifting equipment required for the lift. At no point was there any intention to use it during the installation of the bridge deck.

 

Yes, you're quite right, I'm talking rubbish about the multi-axle. Now I've looked at it again, it wouldn't have been possible to re-position between the two cranes in any case because the outriggers are in the way.

I still don't think there was any intention to rotate the load through 90 degrees though, . . . . why would it make any sense to do that?

[Guest]

I think it would be most interesting to watch how the recovery operation takes place.

Cheers

Gareth

They will need two cranes on a barge.......er.........maybe not.

[magnetman]

Insurance job?

 

(Since we are speculating)

[Global traveller]

Yes, you're quite right, I'm talking rubbish about the multi-axle. Now I've looked at it again, it wouldn't have been possible to re-position between the two cranes in any case because the outriggers are in the way.

I still don't think there was any intention to rotate the load through 90 degrees though, . . . . why would it make any sense to do that?

The reason I see for turning the bridge deck through 90 degrees would be so as to bring the booms and counterweight pretty much inline with the fore and aft line of the barges and in doing so increase the stability of the barges prior to moving them into the narrows for installation. However this is only supposition, but based on previous experience.

[David Mack]

Tony ref your post #32

 

you are correct in your assumption that the deck was to be installed within the narrows, where the bridge abutments are, you are also correct in that the farthest crane slewed too quickly. What we cannot be clear about at this stage is whether the speed of slewing is due to loss of control of the operation due to the instability of the barge or due to other factors, possibly inexperience of the operator.

Having studied all available footage today in conjunction with our marine engineers, we have identified a few contributing factors which I will not post on a public forum, suffice to say that as per what we have seen this is not an operation we would have signed off as being safe.

A clear indication of the proposed operation can be seen from this promotional video shot just before the incident. https://m.youtube.com/watch?v=hNq2qbf-RY8

 

That promo video shows the bridge deck on the third barge, ready to be lifted by the two cranes. But it doesn't explain why the lift was taking place at that location. Why not put the third barge, with the deck in the bridge opening, with cranes either side (on barges or on land), to lift straight from the transport barge to the final location?

Edited August 4, 2015 by David Mack

[Tony Dunkley]

Tony ref your post #32

 

you are correct in your assumption that the deck was to be installed within the narrows, where the bridge abutments are, you are also correct in that the farthest crane slewed too quickly. What we cannot be clear about at this stage is whether the speed of slewing is due to loss of control of the operation due to the instability of the barge or due to other factors, possibly inexperience of the operator.

Having studied all available footage today in conjunction with our marine engineers, we have identified a few contributing factors which I will not post on a public forum, suffice to say that as per what we have seen this is not an operation we would have signed off as being safe.

A clear indication of the proposed operation can be seen from this promotional video shot just before the incident. https://m.youtube.com/watch?v=hNq2qbf-RY8

 

Thanks, that promotional video does show quite clearly what the intentions were. I guess they chose the cranes on pontoons option because the roadway either side and close to the bridge and counterweight pit isn't on solid ground and wouldn't have taken the loading from a crane on either side of the waterway lifting straight from the pontoon with the transportation frame on deck.

The reason I see for turning the bridge deck through 90 degrees would be so as to bring the booms and counterweight pretty much inline with the fore and aft line of the barges and in doing so increase the stability of the barges prior to moving them into the narrows for installation. However this is only supposition, but based on previous experience.

 

Don't really follow your reasoning there, the bridge deck and counterweight assembly were already parallel to the fore and aft line of the pontoons when the lift started, and would have to remain so during final positioning.

The pontoon's stability would not be affected by the orientation of the load as that has no effect on the position of C of G and the point at which the load acts, because it effectively all transfers to the point of suspension at the top end of the crane jibs from the instant the cranes take the full load, at the same time raising the combined C's of G's of the pontoons, cranes and load and reducing the pontoon's GM's to very tiny figures.

Edited August 5, 2015 by Tony Dunkley

[Global traveller]

That promo video shows the bridge deck on the third barge, ready to be lifted by the two cranes. But it doesn't explain why the lift was taking place at that location. Why not put the third barge, with the deck in the bridge opening, with cranes either side (on barges or on land), to lift straight from the transport barge to the final location?

David, whilst this may seem to have been option, you would have ended up with the transport frame obstructing the installation of the deck. Admittedly you could have cut up / unbolted the frame and removed it with a smaller crane situated on one of the abutments, but this would have considerably added to the timeframe and involved personnel working close to a suspended load with all the risks that involves.

As mentioned previously I am of the opinion (and not alone) that the whole operation was poorly conceived, and executed.

Thankfully only minor injuries, material damage and loss of reputation / pride.