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Dreamland Roller Coaster
Eadon Consulting carried out the design of a timber bogie which will be used as an integral part of the rolling stock for the newly refurbished Scenic Railway at Margate Dreamland. The scenic railway was one of the oldest roller-coasters in the country until it was burnt down in 2008. The new railway is based on the same layout and design as the original, however has to meet modern design standards. For more information about the technical aspects of the project click here.
By Piers Turnbull
We had started our involvement with the Scenic Railway project carrying out the calculations and specifications for the reconditioned drive shafts on the rope haulage mechanism which lifts the train up the various inclines on the ride.
One of the other aspects of the job within our client’s scope was the manufacture of bogies for two new trains. The layout of the bogie had to as far as possible match the design of the original. Eadon has experience of timber structures such as lock gates and bridges so we were well placed to assist our client with the timber design aspect. Initially we were asked to carry out an independent check of the original design to the timber eurocode.
Following an initial assessment of the design it was concluded that the current bogie design would not pass the modern day codes in their original configuration. This was quite an interesting aspect of the job as the previous bogies had been running for almost 100yrs, which highlighted how onerous modern design codes are when considering historic structures.
Following the initial check the scope changed from a stress analysis and calculation project to a design project. The two largest sticking points with the original design were the positioning of the main connection bolts relative to the member edges and the characteristics of the structure under lateral loading.
The scope for design change was also extremely limited. Firstly we couldn’t change the outward appearance of the bogie for heritage reasons and secondly the outer space envelope available for the bogie could not change as this was already set by the rail gauge and dimensions of the main rail structure.
The positioning of the main connection bolts used on the original structure didn’t comply with the strict edge and end distance requirements of the code meaning they’re strength could not be used in any calculations. However because it would affect the outward appearance of the bogie they had to be left in the new design despite the fact they could not be used structurally. In addition the lateral load on the bogie due to the train travelling round the track corners meant that the torsion applied to the axle mounting beams was too great and could not be solved by increasing section sizes. To overcome both of these issues we ended up designing an internal box chassis where we could utilise steel for connections and composite sections to better effect without it affecting the outward appearance of the bogie.
The scenic railway is due to open in June 2015 and I am very much looking forward to going to see it up and running. The bogie design was a fascinating job to work on with several unique aspects. It was a great opportunity to put knowledge gained on other timber structures to use on quite a unique project. Additionally the historic nature of the job meant that implementing the design changes required for meeting the modern code were an extremely challenging and rewarding part of the project.