Why is the mersey tunnel not straight

Southport News. Advertise with The Guide. Our video services. Liverpool Wirral Southport Features Business. Lifestyle See All. Gateways linking the city and the Wirral, around 90, vehicles drive through the Mersey Tunnels on any average day. Credit: Philip Brookes. Get all of the latest news for Liverpool and beyond here. Got a story you would like to share with us? Email us at [email protected] and follow us on Twitter , Facebook and Instagram for regular updates for Liverpool.

Share -. You must notify Merseytravel of any change to your address, vehicle registration or personal information. Once you are registered for the scheme our website allows you to amend your address online - the process will treat you like a new applicant and you must prove that you remain eligible for the Liverpool City Region residents discount.

What documents do I need as proof of eligibility? Our online application process, or address change, will automatically verify your residency. However, if this is not possible for any reason, you will be prompted to supply a range of documents to verify your eligibility.

The documents you should supply are: your current driving licence your current council tax bill, or a utility bill with your name and address dated within the last 3 months your V5C vehicle registration form — showing the vehicle is registered to your address.

What if I have multiple cars in my household? Therefore, you can either, have a joint account with your partner or household or each household member can opt to open their own account, assuming of course, each individual can demonstrate and prove they meet the criteria. There is a restriction to four vehicles for each personal account.

Do I have to register to get the discount? Yes, you must register in advance for T-FLOW and demonstrate that you are eligible for this discount. If you do not register, proving eligibility, the full cash toll rate will apply. How much does it cost to register? However, the scheme operates on a pre-payment basis, so during the application process you will be asked to make an initial payment to your account which will add credit so that you can use it straight away. The full amount of your top up is credited towards any journeys.

Your account must always remain in credit and you can set up a regular monthly Direct Debits or top up by debit or credit card online if you prefer.

You can keep a track of your balance online and the lane display messages will also indicate when your balance is running low to alert you to top up your account. Does the Local Residents Discount apply to taxis, driving instructors, or others who use their vehicles for business use? Any business users, including taxis and driving instructors, who meet the criteria for the resident discount scheme and are using their vehicles for private journeys can register for the scheme for private journeys only.

All commercial trips, or trips for a business, through the Mersey Tunnels must be declared and paid for via cash or card. What do I need to qualify for concessionary travel? Do I have to be in the vehicle to use the concession? Yes, it is a condition of issue that is strictly monitored. If you are not in the correct vehicle, or not in the vehicle at all, and someone tries to use the concession, then it may be confiscated.

When will I receive my new allocation of journeys in my account? We will add your new allowance to your journeys automatically on 1st April each year. You cannot carry forward any journeys left in your account on 31st March and they will be cancelled. What do I do if I change my vehicle? If you wish to change your nominated vehicle please call Our staff will be able to help you over the telephone, between 8am and 8pm, Monday to Friday.

Or you can visit a Merseytravel Centre. I want to appeal against a decision to refuse my application You may appeal within one month of the date of your decision outcome. How do I book a Tunnel Tour? How can I get in touch? For Tunnel Fast Tag enquiries please email tag merseytravel.

For all other enquiries please email ask merseytravel. Our telephone number is A considerable influx of water, however, had to be dealt with.

The Liverpool heading was started first and a special drainage heading, 7 feet in diameter, was driven from the foot of the first shaft up a gradient of 1 in to meet the lowest part of the tunnel under the river. Drainage shafts were driven vertically to connect the pilot headings with the drainage heading.

The flow of water in this heading was found to be 2, gallons a minute. On the Birkenhead side, however, the influx of water was found to be considerably less and this could be adequately dealt with by the use of pumps. When the pilot tunnels met beneath the river, all the water drained by gravitation into the Liverpool drainage heading, from which the maximum quantity of water pumped was 4, gallons a minute.

The purpose of the pilot tunnels, each the size of a London Tube railway tunnel, was mainly exploratory. The lower tunnel was driven in advance of the upper heading and vertical boreholes were made to discover the nature of the rock through which the upper tunnel would have to be driven. Similarly, boreholes were driven in advance of the heading to give due warning of any difficulty that might have to be encountered.

Full- Scale Experimental Tunnel Twenty- seven months after the start of the work the two headings met. This was an occasion of great importance. Sir Archibald Salvidge, whose efforts in favour of the enterprise had such great effect, broke through the thin wall of rock. Meanwhile, a full- scale experimental tunnel, feet long, was being built on the Birkenhead side. Because there was no precedent for many of the problems involved in building such a large subaqueous tunnel, the engineers decided that it was necessary to complete a section of the tunnel to find out which method would be most satisfactory.

The most suitable method of procedure was found to be that of excavating the upper half of the tunnel first. As the work progressed the cast- iron lining was fitted in segments of 24 inches. Then the lower half was excavated while the upper semicircle of the lining rested on the natural rock. The upper segments were then bolted together before the support of the rock was removed and the lower segments of the lining erected.

Before the building of this experimental section of the tunnel it had been thought that the segments could not be made longer than 18 inches, but experiment not only proved that it was safe to extend the length of each segment to 2 feet. This reduced the cost of the work but also increased the rate of progress.

Two pilot headings, 15 feet wide and 12 feet high, were driven along the line of the main tunnel for exploratory purposes. Exploratory boreholes were driven ahead of the pilot tunnels to give warning of possible difficulties. The method of erecting the lining was of great importance. Although at certain places it was necessary for the segments, which weighed 17 cwt, to be erected by hand, a special machine was designed to assist the process.

Operated by compressed air, the machine was mounted on a truck which moved on rails laid in the tunnel. The erector had a telescopic arm which could be rotated and was moved as the segments were put in place. The enlargement of the upper pilot heading to the full diameter was the first operation on the main tunnel.

At several points in the upper tunnel rock was excavated into chambers in which the erectors were placed after the first segments of the lining had been fitted by hand. Except when the rock surface was unusually broken or dangerous, enough space was excavated for two segments to be fitted at one operation. In the midstream portion of the tunnel there was a thickness of only 3 ft 6 in of rock between the roof of the tunnel and the bed of the Mersey.

Here it was necessary to support the arch with timbers reinforced by steel bars. Pneumatic hammers were used instead of explosives for excavating in this vicinity. The removal of debris required careful organization.

An electric railway was already laid in the lower pilot tunnel, and it was decided to make use of this.

Chutes were excavated from the upper to the lower tunnel. Down these chutes the debris was shot, and then shovelled into the wagons which were hauled by electric locomotives to either shaft. When the two tunnels were enlarged into one, the railway lines had to be moved, for they impeded the enlargement of the lower semicircle.

A temporary roadway was then suspended from the arch, and the lines were re- laid on this hanging roadway. Lifts at intervals handled the debris, and thus the remaining excavated matter was removed. When the main tunnel had been fully excavated and the lining completed, over 1,, segments had been used, exceeding 80, tons in weight. The greatest care was taken to see that no water leaked into the lining before the segments were backed with cement. The empty space behind the lining was packed by hand with pieces of rock.

In every segment two holes were provided through which thin cement, known as grout, could be injected under pressure. The grout injected was composed of water and neat cement. This was injected at pressures up to lb a square inch, and thus could be forced into neighbouring fissures in the rock as well as filling the interstices in the packing. A further possible source of seepage was through the joints in the lining. About this time the proposals for the tramway were put on hold.

There were various possible reasons for this. One was opposition from Birkenhead who wanted to protect their Ferries, another was that the government had said that they would reduce their contribution if a tramway was laid. The Tunnel would however still be excavated and built for most of it's length with a massive space under the roadway designed for the Tramway.

A further Act was needed in mainly because the siting of the Birkenhead entrance was changed, which led to an increase in costs. The Tolls were now to apply for up to 25 years. In there was a further Act to again change the Birkenhead entrance and also to move the Liverpool entrance from Whitechapel to the Old Haymarket.

But the overall cost and Toll period was the same. This seems to have been mainly due to an incident in an American road tunnel, and a decision that there had to be a massive improvement to ventilation.

This of course wouldn't have happened with a bridge! As the government would not give any more money, the Tolls were now to last for up to 40 years. While all these Acts were being passed the actual construction started at end of It was a mammoth undertaking involving thousands of workers. The main tunnel there were branch tunnels at either end would be 2 miles yards long, and it would be wide enough for 4 lanes of traffic with a total interior diameter of 44 feet.

You can get a bigger version by clicking here:- Workers picture. The tunnel is not very deep, with the lowest point being only feet below high water level in the river. At one point, mid river, there is only 4 feet of solid rock above the tunnel.

Perhaps they were lucky that they didn't get very very wet! The pilot tunnel between Liverpool and Birkenhead was completed on 3 April when Sir Archibald Salvidge broke through the last rock he hadn't done any of the rest of the digging! There were in fact 2 pilot tunnels, with the one for the roadway above that for the tramway. As the bottom pilot tunnel was dug first, did the dignitaries actually shake hands in what would have been the tramway, rather than the roadway?

The construction continued through various difficulties with excavation and drainage, and the unfortunate deaths of workers. The general technique used was to excavate and line the top road half of the tunnel, and then to excavate and line the bottom tramway half of the tunnel. You can get a bigger version by clicking here:- Road deck.

The main Mersey Tunnel has a circular section for most of it's length, presumably due to the tramway. There is a branch tunnel on each side of the river. The branches are semi circles with just a shallow space beneath the roadway.

Part of the land sections of the "tunnel" were not tunnelled; they were built using cut and fill techniques; this includes the part which runs below Dale Street down towards the river. The construction of the tunnel was massive in itself, but it also involved construction of gigantic ventilating machinery, shafts and buildings.