What are the costs of building of a subway

[dwdwone]

I am interested in the average cost of a subway vs the average cost of light rail. I've heard arguments where the two are very far apart, and other that say the difference is minimal. (I'm lumping monorail in with light rail assuming the costs are similar.)

What components go into a subway that make it more expensive?

I would imagine cut and cover is cheaoer than using a TBM. On the other hand, I've seen TBMs up for auction on EBay. So I wonder, what is the reality and how close is it to a bureacracy's interpretation of the costs.

Can anyone help?

[Martin S]

Can't really help with figures dwdwone but the merits of the different types of transport really have to be assessed by cost benefit analysis.

Deep level tunnels, depending on the ground conditions, can be really cheap and are particularly suited to European cities as they seldom have the long, straight streets of US cities that favour cut and cover. The beauty of the deep level tunnel is that the only disruption on the surface is for the construction / ventilation shafts and station entrances - often half a kilometre or more apart.

Cut and cover is probably more expensive to construct as it involves closing off major roads to traffic, restricting access to shops, offices and homes and requires the diversion of services beneath the highway surface, which can be a major problem in a modern city.

The benefits are that the increased access to the worksite makes construction periods shorter, and in the longer term, the larger, rectangular tunnels made easier to construct by this method allow larger trains and stations. Stations are also closer to the surface making them quicker and easier to access and easier to ventilate.

You only have to look at the underground system in London to compare the two methods. The 1860s cut and cover lines, such as the Circle, District and Metropolitan are often accessed by just a staircase, have large stations and large trains and are much cooler in the summer due to being open to the air in many locations. However, their route is dictated by the roads above and they are not as direct as the later tube lines.

The burrowed tube line tunnels are all accessed by lifts or escalators, have very small trains and are often unbearably hot when crowded in the summer. However, they are easier to build, which is why Crossrail will be a burrowed tunnel system even though built to main line gauge.

[RawLee]

Cut'n'cover 1$<mining 5$<TBM 10$

This is the approximate ratio of construction cost.

[GENIUS LOCI]

Wait: if too long cut'n'cover is more expensive than TBM

[RawLee]

What is "too long"? 10km?20km?

[GENIUS LOCI]

It depends: anyway I think over 10 km it begins to be too expensive respect TBM whose rental costs (and assembly-disassembly of course) tend to amortize as length increases, while cut'n'cover, wich has to move at least three times the excavation ground (averegely: it depends how deep it is), remains unchanged

Anyway (always averagely) the difference beetween boring a tunnel and a deep (7m) cut'n'cover is abut 10%: 100M € per Km the first, 80/90M € per Km the second one

[Yardmaster]

Doesn't it make any difference what you are cutting or boring through? Out here, beneath a layer of clay, it is solid basalt, whereas half a kilometre east it is just alluvial silt.

[Jmarius]

Good day to all of you as you know Mexico city at the moment is boulding the 15th subway line of 24 km ant the cost will be around $ 900,000,000.00 nine hundred millions dollars , is about $ 37,000,000.00 millions by km, underground. It will have 40 trains and conectec with 4 others lines. or check Mexico city metro

[siamu maharaj]

Originally Posted by RawLee

Cut'n'cover 1$<mining 5$<TBM 10$

This is the approximate ratio of construction cost.

Mining and TBM are similar except for the technique used to bore the hole, right?

[GENIUS LOCI]

Originally Posted by Yardmaster

Doesn't it make any difference what you are cutting or boring through? Out here, beneath a layer of clay, it is solid basalt, whereas half a kilometre east it is just alluvial silt.

Obviously it makes difference... normally basaltic soil is easier and cheaper to dig as no many consolidations are needed (or nothing at all in many cases)

[Yardmaster]

Originally Posted by GENIUS LOCI

Obviously it makes difference... normally basaltic soil is easier and cheaper to dig as no many consolidations are needed (or nothing at all in many cases)

Unfortunately our basaltic soil is less than a metre deep if you're lucky: from there down it's solid rock.

[mtj73]

Yes, I would say light rail cost's less, there are so many variables, accidents and obstacles when building tunnels, always has been. Building a deep level station is so much more expensive than a glass and concrete box 10 metres above the ground.

Crossrail should give you a good idea of the higher end of the scale, it's well documented and happening now so the cost is relevant. As far as I know the figure of 16 billion GBP includes everything from the compulsory purchases right to the building of the trains. Most of the stations are already there but are going to be completely rebuilt to accommodate the extra line and passengers.

[Basincreek]

According to the price estimates for the new Gold Line EIR in LA a bored tunnel costs about $350,000,000 a mile while a viaduct is about $125,000,000 a mile and a surface grade line is $75,000,000 a mile. These are averages from numerous projects in the US. Other countries will have different average costs.

[dwdwone]

Is most of this cost labor? I mean, conceptually it seems pretty simple. Even with a ground level 1 km line at 75 million, what supports this? The cost of the rails? The EIS? The gravel?

I know my questions sounds a bit naive, but I do wonder sbout these costs, and why they are the way they are.

Consider the cost of building a subway 10 years ago is about 1/10 of what it is today. What element(s) have increased so much that building a line have such astronomical costs?

[Basincreek]

For a surface grade line about 50-70% of the cost is property acquisition. If it is being built on an already acquired and cleared route the price drops dramatically in fact, assuming it is already flat with no surface street crossings to deal with, you can get down to $2,000,000 a mile for both light and heavy rail. Heavy rail gets more expensive because of the need for grade separations but a strange new trend is to build light rail with grade separations which means it will, in the end, cost the same as heavy rail. Viaducts and tunnels are priced the same for both heavy and light rail so if you are going to invest in that you might as well go with heavy rail.

[siamu maharaj]

Originally Posted by Basincreek

According to the price estimates for the new Gold Line EIR in LA a bored tunnel costs about $350,000,000 a mile while a viaduct is about $125,000,000 a mile and a surface grade line is $75,000,000 a mile. These are averages from numerous projects in the US. Other countries will have different average costs.

$350m per mile??? Is that for the first mile, or is the cost the same for every additional mile?

[Shmack]

In 2007 one kilometer in Moscow metro costed $159m. I can't find any figures about deep-laid tunnels, but i believe it is smth astronomical...
Damn, if one sells just one metro line in some big city, he'll be able to buy a fleet of nice nuclear submarines.

[RawLee]

Here,the new metro will cost about 1,7 billion USD, 100% underground,100% bored. Its about 7,5 km long,which means about 226 million USD/km.

I cant tell you the exact cost of everything,but the 10 stations's structures cost about 0,4 billion USD,while the company responsible for the digging won the tender with about 50 million USD. So the tunnel itself costs 6 million USD/km...

[gincan]

In Barcelona they're building a 47,8km metro line that currently is estimated to cost roughly 7 billion euros. That's twice the original cost esimate of 3,5 billion.

[dwdwone]

Exactly. Abd since there is no real estate acquisition when going underground, and a TBM is a fixed cost, why so much? To haul the dirt away? To pay the soil engineers everytime they drill another five feet? For the lining on the tunnel walls?

It makes no sense.