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RAF go from Dambusters to Dam builders
This is not the first time the RAF have been called in recently to assist with flood problems.
https://www.bbc.com/news/uk-england-derbyshire-49199505 Emergency crews are racing to save a damaged reservoir, as "terrified" residents fear their Derbyshire town could be flooded. Water is being pumped out of the 300-million-gallon Toddbrook Reservoir and an RAF helicopter is dropping 400 tonnes of aggregate around it. Part of the dam wall collapsed on Thursday afternoon My concern is how will 400 tonnes of ballast hold 300 million gallons of water!!!! Better pictures and video here. https://www.dailymail.co.uk/news/art...rvoir-dam.html |
Originally Posted by nomorehelosforme
(Post 10534764)
My concern is how will 400 tonnes of ballast hold 300 million gallons of water!!!!
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From what I read they dropped 400 tonnes of aggregate upstream of the dam to divert water from entering the reservoir and other watercourses.
Now they are reinforcing the dam wall. When I was on Mark 2 Chinooks 15 years ago I lifted iso-containers and troops but didn't get to do anything like this! |
This BBC page has a good 1 minute video clip of them postioining and dropping from short lines. I like the careful adjustment after each bag goes down. Also BBC second video.
Reporting that the dam level has been reduced by 2m, which is a heck of a lot. |
Reporting that the dam level has been reduced by 2m, which is a heck of a lot. Nomore helos - the weight of the water on one side needs to be balanced by the weight of the dam on the other, they have simply put more weight on the dam wall where it had previously lost integrity. |
Having watched the video of the Chinook, one of those random questions just popped into mind. Seeing it drop 6 individual bags of aggregate at a time, very carefully and precisely, would it be quicker and/or cheaper to do it with say 6 Jetrangers or 350s (other types are available!), going round and round in a circuit taking one bag each at a time? I’m thinking of the high speed commercial lifting operations that you see with Christmas trees/rocks for dry stone walls, that sort of thing. I have no idea how much a Chinook or a Jetranger costs, how much those bags weigh or if they could even be lifted by such aircraft. And definitely no criticism at all of the job the Chinny is doing, just idle meanderings of the mind while walking the dog. |
One possibility of why the Chinook/s were used is they are:
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Originally Posted by [email protected]
(Post 10535323)
when you see the capability of the high volume pumps they use - and you can see a few of them in the news pictures, they are about half-iso sized boxes - then 2m is quite understandable.
Nomore helos - the weight of the water on one side needs to be balanced by the weight of the dam on the other, they have simply put more weight on the dam wall where it had previously lost integrity. Crab, I started looking at the mathematics of this and gave up! That aside, some good pictures and videos on the Daily Mail |
IIRC the Jet Ranger (B206) can only undersling 1200 lbs, the 350 is probably similar. I understand the Chinook can carry 28,000 lbs. Each bag is, I believe circa 2,000 lbs.
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The bags underneath the Chinook are at least I cubic metre each. A cubic metre of gravel weighs 1.92 tonnes, or 4862 lbs. for short.
Slightly more than the 3,200 lbs. Jetranger's maximum weight. |
Originally Posted by nomorehelosforme
(Post 10535405)
Crab, I started looking at the mathematics of this and gave up! That aside, some good pictures and videos on the Daily Mail
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Originally Posted by Training Risky
(Post 10534941)
From what I read they dropped 400 tonnes of aggregate upstream of the dam to divert water from entering the reservoir and other watercourses.
Now they are reinforcing the dam wall. When I was on Mark 2 Chinooks 15 years ago I lifted iso-containers and troops but didn't get to do anything like this! https://www.independent.co.uk/news/u...se-622283.html |
Originally Posted by chinook240
(Post 10535558)
Nearly 19 years ago, we were doing very similar jobs with the Chinook. Remember, the answer is 2 Chinooks, what’s the question? https://www.independent.co.uk/news/u...se-622283.html |
That's not a hole, THIS is a hole.....
https://i536.photobucket.com/albums/...xttotheSea.jpg https://i536.photobucket.com/albums/...xttotheSea.jpg Photo by Dave G 240 OCU at play. |
Originally Posted by chinook240
(Post 10535558)
Nearly 19 years ago, we were doing very similar jobs with the Chinook. Remember, the answer is 2 Chinooks, what’s the question? https://www.independent.co.uk/news/u...se-622283.html |
Plastic
AS 350 B3 will pick up a tonne ( 1000kg ) bag of ballast. It would be way quicker and cheaper than the RAF. To be fair RAF pilots are not really trained to do repeat lifting like this hours at a time. Would be better on a long line. Normal lift cycle for us would be 1nm a minute including hooking up the load and placing within a ft of the required location. Last time I saw a quote for a Chinnok it was £ 20k an hour, As350 is around £ 1k an hour plus ground crew and pilot We attended the fires last year in Derbyshire, we arrived within 6 hours of being called out, took the military over 2 days to turn up. So would suggest that a civilian operator would be more on call, with better equipment and much more experience |
Exactly how many aircraft can you provide? One small bird is not going to out lift the Chinook in the long run unless the haul is very short and the hook up time for the Chinook is slow. This lifting by the Chinook is not exactly precision lifting but something any reasonably capable pilot can accomplish. The Longline pilot does it all by himself....while the Military Chinook crew uses a crew member and pilot working together to get the load into the correct position. I feel you under state the ability of the RAF Chinook crews to do a days work.....though with all of the HSE requirements, planning, briefing, and related administrative hurtles....it would take them a while to actually get to work as compared to the civil operator. You have a point about using long lines....but then the military (RAF and US Army for sure) do not embrace that technique as a normal role or operational skill. The military always seems to have a longer lead time and shows up with far larger a support crew than does a comparable civilian operator....been there and did that on both sides of the equation. |
The time to call the military is all about red tape and paperwork. But, as I said, I strongly suspect that the real cost of this will not be passed on as it is a great training exercise. The politicians will also see it as PR. So the cost is, effectively, greatly reduced.
The Canal and River Trust estimated on Saturday that 105,000 cubic metres (23 million gallons) of water had been pumped out in 12 hours.An RAF Chinook helicopter put 400 tonnes of sandbags on the affected part of the dam on Friday - adding a further 70 on Saturday. In one report about the residents who refuse to leave their homes prattle the classic "Health and Safety gone mad" It would be interesting to know what he would/will say if his house was swept away and his family with it ... |
“We attended the fires last year in Derbyshire, we arrived within 6 hours of being called out, took the military over 2 days to turn up.” I’m sure that has nothing to do with military response times, in fact I know it hasn’t, more to do with political decision making. “RAF pilots not really trained to do repeat lifting” Really, not sure what special training there is for lifting one load followed by another, isn’t that what they’re doing right now. I’ve spent 8 hours a day doing exactly that in a Chinook. PS. Could you do it safely in 1.5 k vis, 500’ and in 1 mulch, which I suspect was the challenge given the late start time and forecast weather? |
There's some poor information being posted about what RAF helicopter pilots are trained, or not, to do with underslung loads..
Load lifting on a 100 foot strop certainly wasn't uncommon in my time - it was often an essential tool, such as when the army put loads next to tall trees, instead of out in the open, to avoid giving away their position. Not trained for repeat load lifting...? I assume you have never seen an army Brigade lift. |
I overheard an interesting conversation last night in a restaurant (I admit I cannot verify what was said so it's definitely rumour only).The gist of it was that dams like this were built with side spill outlets controlled by valves. These are meant to be used to control the maximum water level, to prevent over-topping of the wall but unfortunately these valves could no longer be opened at this dam, because the mechanism has rusted solid over many years.
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Originally Posted by ShyTorque
(Post 10536452)
I overheard an interesting conversation last night in a restaurant (I admit I cannot verify what was said so it's definitely rumour only).The gist of it was that dams like this were built with side spill outlets controlled by valves. These are meant to be used to control the maximum water level, to prevent over-topping of the wall but unfortunately these valves could no longer be opened at this dam, because the mechanism has rusted solid over many years.
Somewhere I have a photo of Laggan Dam (adjacent to the A86 Spean Bridge - Kingussie road) in full spate, the amount of water being released is astonishing. The mist of spray it created could be seen from several miles away. Standing next to it was truly awesome. What I am curious about is where the bags being lifted are coming from. |
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Shy,
Load lifting on a 100 foot strop certainly wasn't uncommon in my time |
Originally Posted by ShyTorque
(Post 10536452)
I overheard an interesting conversation last night in a restaurant (I admit I cannot verify what was said so it's definitely rumour only).The gist of it was that dams like this were built with side spill outlets controlled by valves. These are meant to be used to control the maximum water level, to prevent over-topping of the wall but unfortunately these valves could no longer be opened at this dam, because the mechanism has rusted solid over many years.
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Originally Posted by chinook240
(Post 10536486)
https://cdn.newsapi.com.au/image/v1/...698fe2230efdd1 https://pbs.twimg.com/media/EBB0QohWkAAdDWI.jpg |
Merely pointing out the following
As 350 would be quicker, cheaper and more accurate with a longline, reasons 1. Longline with single pilot more accurate so bags could be placed not dropped 2. The pick up could be much closer to the dam and hence shorter flight time 3. Pilot would be more used to a high number of cycles per hour along with the crew eg probably a bag every 1.5 minutes or so 4. Like flying on instruments lifting quickly and safely and accurately is a perishable skill 5. Takes seconds to hook a bag on to a longline hook 6. Most RAF pilots don't do it that regularly. I am just a novice at doing it as i have around 700 hours lifting. The military dont fly a huge amount of hours and not solely lifting, not their fault it is all to do with budgets. It is really tools for the job. I would agree that great training exercise, great PR for RAF and shows the public that we sorely need our military. but the question was is it cheaper and more efficient ! |
If you can't get the bags closer because the roads are closed then the distance is the same.
What level of accuracy do you think could improve on a couple of centimetres - which is what was stated on the TV? USL flying is absolute bread and butter to SH crews. How much would a 350 operator charge the Govt for the service? Is one 350 with a single bag really 3 times more efficient than one Chinook with 3 bags under it? |
Originally Posted by chinook240
(Post 10536486)
If you mean PUP, I’ve seen it’s Long Hill |
Originally Posted by SASless
(Post 10536491)
Shy,
Was it done by Vertical Reference Long Line techniques....doors off or with bubble window doors.....or was the Crewman in back leaning out and providing directions to the Pilot flying. |
Originally Posted by Pozidrive
(Post 10536543)
What you overheard was absolute nonsense. The current pictures clearly show the weir at the top of the spillway. This controls the maximum level, no valves involved. Outlet valves will be at the bottom, possibly in a tunnel within the dam. These will be in regular use to control the flow from the reservoir, and will be maintained in good working order, certainly not allowed to "rust solid over many years".
There is now a new page on the BBC news site showing a photo attributed to the Canal and River Trust which shows the face of the dam. The "weir" is annotated as "Auxiliary Spillway" and appears to have been added later. The main spillway is lower down, as I was led to understand. If the main spillway was serviceable, why is the water being pumped out from above (difficult, very expensive and potentially dangerous), rather than being allowed to drain naturally from below through the valves (i.e. main spillway)? https://www.bbc.co.uk/news/uk-englan...shire-49220650 |
Crab
What is the roads closed got to do with it ? If you are the emergency services then you open them ! Lets assume that the bags are a mile from the drop zone, I suspect and knowing the area one could get them way closer. Then the 350 will have a turn round time of around 2 mins per bag. So 400 bags is 800 minutes or 13.3 hours call it 15 to be on the safe side. We would have 2 pilots so at a real push could do those bags in a day AS 350 £15000 Positioning £ 4000 Crew x 2 days £ 1800 Jet a1 £ 1800 Contingecy 15% £ 3120 So £ 25720 is the bill my company would charge. I might be wrong on teh distance, but that would be the advantage of the 350 and a longline. Did you notice the bag rolling down the hill on the news ? |
You still haven’t confirmed your ability to continue through the night in poor weather? |
What is the roads closed got to do with it ? If you are the emergency services then you open them ! As Chinook 240 has pointed out - will you manage 24-hour ops in poor weather? |
Originally Posted by ShyTorque
(Post 10537290)
Two points:
There is now a new page on the BBC news site showing a photo attributed to the Canal and River Trust which shows the face of the dam. The "weir" is annotated as "Auxiliary Spillway" and appears to have been added later. The main spillway is lower down, as I was led to understand. If the main spillway was serviceable, why is the water being pumped out from above (difficult, very expensive and potentially dangerous), rather than being allowed to drain naturally from below through the valves (i.e. main spillway)? https://www.bbc.co.uk/news/uk-englan...shire-49220650 |
Originally Posted by [email protected]
(Post 10537360)
Because if you have evacuated an area because of the risk to life from the dam bursting, you would look pretty silly sending a load of civilian lorries inside that area if the dam did give way - it's just a sensible precaution you are happy to ignore to try and support your point about using a 350.
As Chinook 240 has pointed out - will you manage 24-hour ops in poor weather? |
Originally Posted by Pozidrive
(Post 10537377)
The map in post #23 shows the pick up point is a couple of miles outside the evacuated area, and at a higher elevation. The photos I added show a road across open moorland, no trees, no street lights, no utility poles - looks like as good a place as any.
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Crab
So what is the cost of a chinnok then, i have told you how much I would do the job for, so money where your mouth is, how much is your chinook going to cost with all the crap that goes with it ? Bet you the RAF can't even get close.to my cost. I am afraid the military is no where near as efficient as you think . Just because you can lift a 105 or an ISO container doesn't put you up there as utility Gods I am afraid |
At the risk of boring. The cost of the Chinook and crew is unknowable. If they were not doing this repair, they would be doing normal exercise and training. You cannot easily calculate the cost per hour of items that are budgeted per year and NEVER intended to be sold by the hour. That's not what the Army do. When they are called in to lay sandbags and rescue people - is that charged? Do the local govt work out which commercial company could do that and how much first?
The cost of a commercial outfit is known, because that is what they do and are set up to charge by the hour/day or whatever. But, it is my contention, the Govt is going to tell the MoD to NOT charge the cost to anyone. So you cannot work out the cost. Lastly, I think that many tax payers would rather the Army do this than a commercial outfit. |
I thought under a national emergency then the military will not charge for their services? You may have to go a little cheaper Hughes500? |
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