2 feet per hour

[Amarillo]

I’d have thought that a giant tunnelling machine could manage better than 2 feet per hour!

HS2 boss hopes UK ‘gets behind’ project after launch of huge tunnelling machine | ITV News

It will work non-stop for three years and is one of 10 tunnel boring machines being used between London and the West Midlands for Phase 1. | ITV News London

www.itv.com

 

[jimmywease]

Sounds quite quick to me. I didn’t watch the link though - a lot of civil engineering is boring...

 

[kurienp]

I’d have thought that a giant tunnelling machine could manage better than 2 feet per hour!

HS2 boss hopes UK ‘gets behind’ project after launch of huge tunnelling machine | ITV News

It will work non-stop for three years and is one of 10 tunnel boring machines being used between London and the West Midlands for Phase 1. | ITV News London

www.itv.com

I like the names - Florence and Cecelia. Any reason why they did not call them Harry and Paddy?

 

[B J G]

Has to cut the train size tunnel hole, remove the material and put the new concrete sections in place leaving a completed tunnel behind. 24/7 operation

 

[Borris]

I'd rather Florence and Cecelia had something better to do with their time!

 

[GrumpyGranddad]

Has to cut the train size tunnel hole, remove the material and put the new concrete sections in place leaving a completed tunnel behind. 24/7 operation

A lot of the ‘spoil’ from the tunnels gets put onto trucks to be driven to the Vale of Aylesbury to build the embankments I believe. So lot’s of heavy traffic coming past Wendover ! :-(

 

[GrumpyGranddad]

I like the names - Florence and Cecelia. Any reason why they did not call them Harry and Paddy?

Does Paddy translate to Meghan?

 

[flying banana]

48ft of tunnel cut . Waterproofed and lined with concrete blocks in one day is quite a speed

 

[Amarillo]

48ft of tunnel cut . Waterproofed and lined with concrete blocks in one day is quite a speed

Florence and Cecilia are 558 ft long, at 48 ft a day it will take 11 or 12 days for them to pass 48 ft of tunnel.

 

[flying banana]

I see. Thought 2ft per hour times by 24 hrs was my reasoning. Depending in the strata

 

[soulstyledevon]

I like the names - Florence and Cecelia. Any reason why they did not call them Harry and Paddy?

Should’ve called them Environmental & Disaster...

 

[flying banana]

Should’ve called them Environmental & Disaster...

Hurricanes should all be given female names. Because when you first meet them they are warm wet and wild. But when they've gone they have took your house and car with them.

 

[Borris]

Florence and Cecilia are 558 ft long, at 48 ft a day it will take 11 or 12 days for them to pass 48 ft of tunnel.

They should try Sennapods.

 

[Kevthegas]

I was in my local builders merchant today, they say there is a national shortage of cement
at the moment. HS2 project is getting the blame for buying it all up ??

 

[jimmywease]

I was in my local builders merchant today, they say there is a national shortage of cement
at the moment. HS2 project is getting the blame for buying it all up ??

I think they mean that HS2 is suffering less (than construction) from the huge fluctuations in supply and demand for materials, caused by covid (plus Brexit? plus Suez?).
This is surely because HS2 would have calculated and procured cement long ago, on a grander scale, with water-tight contracts.

 

[Velma's Dad]

A lot of the ‘spoil’ from the tunnels gets put onto trucks to be driven to the Vale of Aylesbury to build the embankments I believe. So lot’s of heavy traffic coming past Wendover ! :-(

I just did a calc: if 2 x 9 m dia tunnels at 48 ft (14.3m) a day that's about 1,800 m3 of spoil a day to get taken somewhere. You have to multiply that by about 1.75 to allow for 'bulking up' of the material after excavation so that becomes about 3,100 m3, multiplied by about 1.2 tonnes per m3 becomes 3,800t per day which is 190 x 20t tipper truckloads a day.

Even if all of that passed along the A413, and no movements between 10pm and 7am say, that would only be about one truck every five minutes in each direction, so hardly the nose to tail convoys that some people around here have catastrophised about. The A413 around Amersham carries about 8,000 vehicles a day in any case (I live in a village off that main road).

Still, it's quite a pile of chalk.

 

[andyinluton]

Theres a team of 17 on each machine and a further 100 people at surface level in support. They are working 24 hours per day so that would normally be 3 shifts - if they each drive to work & home again individually thats another 1000 vehicle movements.

Add in a good few cement & reinforcement deliveries & the numbers soon add up.

All the above also only get you a lined tunnel, there's still track, track bed etc etc

 

[Amarillo]

I just did a calc: if 2 x 9 m dia tunnels at 48 ft (14.3m) a day that's about 1,800 m3 of spoil a day to get taken somewhere. You have to multiply that by about 1.75 to allow for 'bulking up' of the material after excavation so that becomes about 3,100 m3, multiplied by about 1.2 tonnes per m3 becomes 3,800t per day which is 190 x 20t tipper truckloads

Did I read somewhere that they are adding water to the spoils to turn it to slurry?

If so, could they be pumping it away, or is that just fanciful thinking?

 

[DrewVW]

Sounds quite quick to me. I didn’t watch the link though - a lot of civil engineering is boring...

Wholly boring!

 

[WelshGas]

Did I read somewhere that they are adding water to the spoils to turn it to slurry?

If so, could they be pumping it away, or is that just fanciful thinking?

Correct.

 

[Velma's Dad]

Did I read somewhere that they are adding water to the spoils to turn it to slurry?

If so, could they be pumping it away, or is that just fanciful thinking?

I dunno, but water has been a big concern generally around here. The chalk is an aquifer and we have regular water supply issues - mainly due to a chronic deficiency of infrastructure investment and maintenance since privatisation - but people are quite nervous about HS2 messing things up further. Certainly there's had to be a huge work programme to divert ground water down in the Missenden valley to avoid pollution during HS2. The chalk stream river is massively sensitive to groundwater levels and if it dries up during the works (which it indeed did about 20 years ago, due to over-abstraction) there will be hell to pay locally.

Unfortunately in my opinion the HS2 management have done themselves no favours on the way the public info has been handled on all that. The risk assessments were all done behind closed doors and on a "trust us we know what we're doing" basis.

 

[WelshGas]

What I find mind boggling is the impact just one of these machines has on the economy in the wider sense, especially as we come out of the Pandemic.
Each machine operates 24/7. On board crew of 17 and a surface crew of 100. To provide 24/7 cover for work, holidays and training etc then that is approximately 6 WTE / post so 702 employees. Then we have the impact these employees have on the wider economy, ranging from childcare, NHS, public/private transport, leisure, hospitality etc etc. let alone the public finances through direct and indirect taxation. The numbers are significant.
I'm sure someone with expertise will be able to work out the full impact.

 

[Velma's Dad]

What I find mind boggling is the impact just one of these machines has on the economy in the wider sense, especially as we come out of the Pandemic.
Each machine operates 24/7. On board crew of 17 and a surface crew of 100. To provide 24/7 cover for work, holidays and training etc then that is approximately 6 WTE / post so 702 employees. Then we have the impact these employees have on the wider economy, ranging from childcare, NHS, public/private transport, leisure, hospitality etc etc. let alone the public finances through direct and indirect taxation. The numbers are significant.
I'm sure someone with expertise will be able to work out the full impact.

Yes it's immense. Last year there were inevitably yells for HS2 to be scrapped because it wouldn't be affordable due to the covid economic impact. But I was sure it would go ahead, as big infrastructure projects are exactly the kind of economic stimulus that are looked for in recessions. It's certainly having some effect already - I was told that electricians' hourly rates are going up around here because the demand from HS2 is creating a shortage. If there's a big post-pandemic bounce-back in the general economy, which looks likely, construction related trades are going to be in very high demand for the next couple of years and anyone planning a house extension may be in for a shock.

 

[Lightning]

Yes it's immense. Last year there were inevitably yells for HS2 to be scrapped because it wouldn't be affordable due to the covid economic impact. But I was sure it would go ahead, as big infrastructure projects are exactly the kind of economic stimulus that are looked for in recessions. It's certainly having some effect already - I was told that electricians' hourly rates are going up around here because the demand from HS2 is creating a shortage. If there's a big post-pandemic bounce-back in the general economy, which looks likely, construction related trades are going to be in very high demand for the next couple of years and anyone planning a house extension may be in for a shock.

Apparently there is a worldwide shortage of lumber at the moment, prices have rocketed and construction projects are being put on hold.

 

[GrumpyGranddad]

I was planning to make a fortune in retirement selling bacon sandwiches from my Cali to the HS2 workers in a layby on the Wendover by-pass, but somebody beat me to it.