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Posted By Robert. Stephenson

A very singular and interesting proposition has been made by Richard Badnall, for travelling upon undulating lines 6f railway in preference to straight or level lines, with the view of saving locomotive power, by the application of the natural force of gravity in the descent, so as to obtain a great momentum in making the succeeding ascent. His plan is best explained by himself in the specification of a patent, dated the 8th of September, 1832, which he obtained for that object. "If a plummet suspended by a string, from the point z, be drawn away from the perpendicular line to the point a, and there let go, it will fall by its gravity to b, in the arc a b; but, in its falling, it will have acquired so much momentum, as will carry it forward up to a similar altitude at the point c.

 

 

Fig.1. Fig. 2UndulatingUndulating

 "Let it be supposed that a line of rails, or tram-way for carriages, be so constructed from the summit of two hills, as Fig. 2, across a valley, that the descent from one hill, as a, to the valley b, shall subtend a similar angle from the horizontal line to the ascent up the other hill from b to c. Now if a train-waggon, as d, be placed at the summit of the declivity a, it will, by its gravity alone, run down the descending line of rails, to the lowest point b; but in so running, according to the principles of the oscillating pendulum, it should have acquired a momentum that would carry it forward without any additional force up the ascending line to the summit of the hill c, being at the same altitude as the hill a. It is quite certain that this would really take place if the force acquired by the momentum was not impeded by the friction of the wheels of the carriage upon their axles, and upon the rails on which they run. Hence, subtracting the amount of friction as a retarding force from the momentum which the carriage has acquired in descending from a to b, it will be perceived, that the force of momentum alone would only impel the carriage part of the way up the ascent b c, say as far as z. It must now be evident, the carriage d would not only pass down the descending line of road from a to b by its gravity, but that the momentum acquired in the descent would also impel it up the second hill as far as z, unassisted by any locomotive power. In order, therefore, to raise the carriage to the top of the second hill, I have only to employ such an impelling force as would be sufficient to drive it from z to c, the whole expense of locomotive power for bringing the carriage from a to z being saved. If now I employ a locomotive power to assist in impelling my carriage from a to b, I, by that means, obtain a greater momentum than would result from the descent of the carriage by gravity alone, and am enabled by that means to surmount the hill c, having travelled the whole distance from a to c, on the undulating line of road, with the exertion of much less locomotive power than would have been requisite to have impelled the carriage the same distance upon a perfectly horizontal plane." Having thus explained the principle of his invention, Mr. Badnall claims the formation of tram and railroads, with such undulating curves as are adapted to his object. This invention has been the subject of much able controversy in the Mechanics' Magazine, and some other public journals, of which our limits render it impossible to give any account.

 
Posted By Robert. Stephenson


The skew bridge at Rainhill station

The skew bridge at Railhill station

Even to the most untrained of eyes, it’s clearly not the kind of workmanship likely to win the approval of as exacting a taskmaster as George Stephenson.

So it is understable the work undertaken at Rainhill’s Skew Bridge, an engineering first which has stood the test of time since it was built in 1829 by Stephenson, raised more than just afew eyebrows.

Local historians were horrified when it was subjected to a horrendously botched renovation job by Network Rail, who wanted to raise the bridge to help them electrify the line.


Contractors had hoped to raise the entire length of the historic bridge, including the wing walls on either side, to help them electrify the line between Liverpool and Manchester.

But the type of stone used proved a particularly poor match and they found they were unable to remove the original copingstones as the vibrations created could have damaged the parapet - including the plaque on the rail face.

Skew Bridge was constructed by Stephenson in 1829 and is a Grade II listed structure.

It spans the Liverpool to Manchester railway line and is widely accepted as the world’s first bridge to cross a railway line at an angle.

Network Rail bosses insisted that they fully appreciated and understood the importance of Skew Bridge - both from a railway history perspective and as an aesthetically significant asset in Rainhill.

They also pledged, from now on, to use sandstone more befitting of the existing structure.

Among the 21 objection letters received by St Helens Council was one from Rainhill Civic Society, which even enclosed a note from an architect on their planning group as to how the works could be improved.

It read: “The society wish to register their disappointment and disapproval at the work carried out at Skew Bridge, a bridge which is of considerable historic significance.

“They do not consider the modifications to have been carried out in the best or most appropriate way.”

However Network Rail’s revised plans were approved by the planning committee subject to conditions - including that a qualified stonemason is called in to oversee the works.

A spokesman for Network Rail simply declined to comment on the first attempt at raising the Rainhill bridge, but added: “Naturally, we want the work to be carried out to the highest standard and recognise that this is important both for local residents and rail users alike.”

 


 
Posted By Robert. Stephenson

Puffing Billy Festival Talks Programme

 

 

 
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