The Railway Conquest of the World

by Frederick Arthur Ambrose Talbot

The Scandinavian peninsula has been the battle-ground of many titanic struggles on behalf of the railway. In this country the iron horse has forced its way to the most northerly point in the world where the shriek of a locomotive whistle may be heard. This is Ofoten, a port on the Atlantic seaboard of Norway, beyond the 68th parallel, and well into the Arctic circle, where the famous iron mines of Gellivare in Sweden find a western point for shipping the ore.

It was in Sweden that steel was pressed into service for the first time in connection with the erection of bridges by the late Major C. Adelsköld, R.E., and Member of the Academy of Sciences. This was so far back as 1866, and the daring engineer designed, superintended the preparation of the metal, and also the erection of the bridge. The claim of being the first steel bridge has been advanced on behalf of other structures in different parts of the world, but the records are against all such statements, for they were anticipated by a decade at least in a convincing, practical manner.

Major Adelsköld’s bridge is highly interesting, not only from the historical point of view, but because of its unusual design, and the methods adopted in its erection. Through the courtesy of Madam Gustafva Adelsköld, I am enabled to give the following particulars of its evolution and construction.

The bridge was designed to carry the Uddevalla-Wenersborg-Herljunga railway across the Huvudnas Falls, just above the Tröllhätten Falls. At this point the Göta River forces its way through a gorge 137½ feet wide, just above a fall over a lofty ledge of rock. The depth and velocity of the water prevented any intermediate pier being erected in the waterway, so in order to span the gap it was necessary to lift the girders bodily to set them into position. To enable this end to be achieved it was imperative that the main girders should be as light as possible. An iron girder, which was the metal in exclusive vogue at that time for this work, 153 feet in length by 12 inches wide, of the requisite strength, would have weighed over 700 tons, and to have handled such a weight would have demanded expensive and elaborate erecting tackle.

Major Adelsköld consequently rejected iron as the structural material in favour of light steel girders. Once these were set he anticipated no further hindrance to completing the structure as a “suspension bridge.” Up to this time steel girders never had been employed in such work, and the engineer, when he revealed his intentions, was urged by experts and fellow-craftsmen not to use “such a brittle and untrustworthy material” for so long a span.

Major Adelsköld, however, was convinced of the soundness of his proposal, and consequently continued his efforts in the face of spirited opposition. The bridge was built at Bergsund, and the dimensions were calculated for a strain of 8 tons per square inch, though the metal was tested to twice that stress before being set in position. The total weight was only 50 tons.

From the engineering point of view the design is considered somewhat novel, for it bears no resemblance to the general conception of a suspension bridge. It is an inverted structure of this class. The upper members act merely as struts to keep apart the ends of the chains below, which really carry the load through the medium of the triangular members.

The method by which the structure was erected was quite as interesting as the design of the bridge itself. The girders were brought to the western bank of the river. To swing them into position a derrick was rigged up on either bank so as to overhang the water. The outer ends of these masts, which measured 60 feet in length, were fitted with heavy pulleys, over which ropes were passed and carried from capstans installed for hauling purposes. The pulley ropes on the eastern bank were pulled across the waterway and secured to one end of the girder, while the western bank pulley ropes were secured to the other end of the steel member, which measured 153 feet in length. In this way the girder was lifted, swung over the water, and lowered into position. The event was regarded as so unusual that crowds of people from Gothenburg and Tröllhätten assembled on the banks to witness the setting of the steel on February 8, 1866.

Owing to the roar of the waters, the engineer could not make his voice heard, so orders were communicated across the river in Morse code by hand-signalling. The first girder was lifted and set in position in thirty minutes, while the second was handled in half that time. Once the girders were set it was an easy matter to complete the remainder of the structure.

It may be interesting to relate that the total cost of setting the main girders, together with the hire of the tackle borrowed from a Gothenburg shipbuilding-yard, and including the wages of the men assisting in the task, was only £25, or $125. At that time Major Adelsköld’s feat was regarded as an audacious stroke of engineering, but to-day steel is the exclusive material employed in the erection of bridges.