Aug 022013


On this date in 1870 the Tower Subway under the Thames in London opened for service.  Technically it was the first tunneled underground railway in the world.  The Metropolitan Underground Railway in London (opened in 1863), predates the Tower Subway, but it was not built by tunneling, but by the cut-and-cover method.  Cut-and-cover involves excavating a deep trench, laying tracks, and then roofing the trench over.  True tunneling, represented by Tower Subway, involves excavating entirely underground.  There was an entrance on Tower Hill and another on Vine Street on the South Bank .


Passengers were carried down to the subway in a steam powered lift. Once down, they would get into a narrow gauge railway carriage which was attached to a cable, and get winched through the tunnel to the other side. Before the subway was built commuters had to take ferries to cross the river.


In 1864 Peter William Barlow patented a method of tunneling using a circular wrought iron or steel shield and filling the gap between the tunnel lining with lime or cement to prevent settling of the ground above. He published a pamphlet in 1867 suggesting a network of tunnels with cars carrying up to 12 people. In 1868 authority was obtained for a tunnel under the Thames between Great Tower Hill and Pickle Herring Stairs near Vine Street (now Vine Lane). Work began in February 1869 with the boring of entrance shafts, 60 feet (18 m) deep on the north bank and 50 feet (15 m) deep on the south bank. The horizontal  tunneling itself started in April and, using the circular shield, a tunnel 1,340 feet (410 m) long was dug with a diameter of 6 feet 7 3?4 inches (2.026 m), a maximum of 66 feet (20 m) below the high water level. This was bored through a stable layer of the London clay that lay 22 feet (6.7 m) below the river bed, below the soft alluvial deposits that had plagued earlier attempts at tunneling under the river.

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The subway was not a financial success because it was slow, cramped, and expensive, with long waits to make the crossing.  A regular one way ticket was 1 d. and a “first class” ticket was 2 d (an hour’s wage for a skilled worker). The higher fare did not provide better seating, only that the passenger could jump to the head of the line.  By December the subway company declared bankruptcy, and the railway was abandoned.  The tunnel was converted to pedestrian use with spiral stairways replacing the lifts.  The fare to cross was reduced to ½ d.

The Italian writer Edmondo De Amicis (1846–1908) gives a description of a passage through the subway in his Jottings about London:

“As I was thinking of these things I disappeared from the world indeed, going down a lighted spiral staircase which buries itself in the earth on the right bank of the Thames, opposite the Tower. I went down and down between two dingy walls until I found myself at the round opening of the gigantic iron tube, which seems to undulate like a great intestine in the enormous belly of the river. The inside of this tube presents the appearance of a subterranean corridor, of which the end is invisible. It is lighted by a row of lights as far as you can see, which shed a veiled light, like sepulchral lamps; the atmosphere is foggy; you go along considerable stretches without meeting a soul; the walls sweat like those of an aqueduct; the floor moves under your feet like the deck of a vessel; the steps and voices of the people coming the other way give forth a cavernous sound, and are heard before you see the people, and they at a distance seem like great shadows; there is, in short, a sort of something mysterious, which without alarming causes in your heart a vague sense of disquiet. When then you have reached the middle and no longer see the end in either direction, and feel the silence of a catacomb, and know not how much farther you must go, and reflect that in the water beneath, in the obscure depths of the river, is where suicides meet death, and that over your head vessels are passing, and that if a crack should open in the wall you would not even have the time to recommend your soul to God, in that moment how lovely seems the sun! I believe I had come a good part of a mile when I reached the opposite opening on the left bank of the Thames; I went up a staircase, the mate of the other, and came out in front of the Tower of London.”

The subway became a popular way to cross the river, averaging 20,000 people a week (a million a year). Its main users were described as “the working classes who were formerly entirely dependent on the ferries.” However, in 1894 the toll-free Tower Bridge opened a few hundred yards downriver, causing a drop in the subway’s income. In 1897, Parliament passed an Act authorizing the sale of the tunnel to the London Hydraulic Power Company (LHPC) for £3,000, and the subway closed to passenger traffic in 1898. It was subsequently used to carry hydraulic power mains and water mains. To this day water mains run through the tunnel. The hydraulic tubes are gone, replaced with modern telecommunications cables.

A small round entrance building survives at Tower Hill near the Tower of London’s ticket office, a short distance to the west of the main entrance to the Tower. This is not the original entrance, but was built in the 1920s by the London Hydraulic Power Company, with a ring of lettering giving the original date of construction and naming the LHPC. The entrance on the south bank of the Thames was demolished in the 1990s, and a new one has been built in its place. It is located just behind the Unicorn Theatre on Tooley Street, but there is no plaque to mark the site.

To celebrate the opening of this tunnel I give you the amazing Tunnel of Fudge Cake.  It is a circular bundt cake that develops a tunnel of fudge through the middle as it bakes.  The original recipe, which you can read in the image below (click to enlarge) was a runner-up in the 1966 Pillsbury Bake-Off. It was an instant favorite because of the magical fudge tunnel. However, this original recipe calls for a product that is no longer in production: Pillsbury’s Double Dutch Fudge Buttercream Frosting Mix. There was much weeping and wailing in home kitchens with cooks searching for a substitute, much to the bafflement of Pillsbury executives who explained that the frosting mix was nothing more than a blend of cocoa powder and powdered sugar (which could be substituted and still produce the desired results). To appease the hordes they revamped the recipe and posted it on their website. They even added a chocolate glaze. Apparently 2 packages of Jiffy Chocolate Frosting Mix can also be used as a substitute for the frosting mix.  Take your pick.

tunnel1  tunnel11

Here is Pillsbury’s new recipe copied from their website.  The only other things to note are that the cake must not be overcooked otherwise the fudge will be absorbed into the cake, and that the tunnel will not form without the nuts.  I have not made this, but both recipes have been thoroughly tested. As per the notes, use an oven thermometer to ensure accurate cooking temperatures.

Tunnel of Fudge Cake



1 3/4 cups sugar
1 3/4 cups margarine or butter, softened
6 eggs
2 cups powdered sugar
2 ¼ cups Pillsbury BEST® All Purpose or Unbleached Flour
3/4 cup unsweetened cocoa
2 cups chopped walnuts*


3/4 cup powdered sugar
1/4 cup unsweetened cocoa
4 to 6 teaspoons milk

Step 1. Heat oven to 350°F. Grease and flour 12-cup fluted tube cake pan or 10-inch tube pan. In large bowl, combine sugar and margarine; beat until light and fluffy. Add eggs 1 at a time, beating well after each addition. Gradually add 2 cups powdered sugar; blend well. By hand, stir in flour and remaining cake ingredients until well blended. Spoon batter into greased and floured pan; spread evenly.

Step 2. Bake at 350°F. for 45 to 50 minutes or until top is set and edges are beginning to pull away from sides of pan.** Cool upright in pan on wire rack 1 1/2 hours. Invert onto serving plate; cool at least 2 hours.

Step 3. In small bowl, combine all glaze ingredients, adding enough milk for desired drizzling consistency. Spoon over top of cake, allowing some to run down sides. Store tightly covered.


* Nuts are essential for the success of this recipe.

** Since this cake has a soft filling, an ordinary doneness test cannot be used. Accurate oven temperature and baking times are essential.