TITLE: The Forth Bridge NAME: Christian Radek, Ph.D. COUNTRY: Germany EMAIL: christian.radek@dortmund.netsurf.de WEBPAGE: http://home.netsurf.de/christian.radek/ TOPIC: Landmarks COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT. JPGFILE: cr_forth.jpg ZIPFILE: cr_forth.zip RENDERER USED: Povray 3.1e.watcom.win32 TOOLS USED: none RENDER TIME: 58' 42" HARDWARE USED: AMD K6-II 300MHz 64MB IMAGE DESCRIPTION: The image depicts the rail bridge across the Firth of Forth (Scotland), commonly known as 'The Forth Bridge'. The Forth Bridge can be viewed as a landmark in Scotland but also as a landmark in engineering - i.e. in the transition from cast iron bridges to steel bridges. The Forth Bridge was constructed between 1882 and 1890. The zip file contains three small images which show different stages of construction. If one considers the tools available at that period of time, building the bridge was a great achievement. Here are some figures: Total length of the bridge including both approach viaducts 8,296 ft Length without viaducts ................................... 5,330 ft Two main spans ............................................ 1,170 ft each Length of cantilever ...................................... 680 ft Maximum height ............................................ 343 ft Clear height for shipping ................................. 150 ft Weight .................................................... 50,958 tons Total number of rivets .................................... 7 million Maximum number of people employed in 1888 ................. 4,600 Deaths .................................................... 57 At the time of completion the Forth Bridge was the largest girder type bridge in the world until the completion of the Quebec Bridge in 1917. The barrel in the image is a reminder that the bridge has to be painted every 4 years, a task which lasts 4 years. Literature: Firth of Forth and Firth of Tay - Two Railway Bridges of an Era Arnold Koerte, Birkhaeuser Verlag Basel Boston Berlin 1992 ISBN 3-7643-2444-9 (Basel...) ISBN 0-8176-2444-9 (Boston) 100Yrs of the Forth Bridge Roland Paxton, Thomas Telford Limited London 1990 ISBN 0-7277-1600-X The Forth Bridge - A Picture History Sheila Mackay, HMSO 1993 ISBN 0-1149-5183-7 DESCRIPTION OF HOW THIS IMAGE WAS CREATED: The main priority in creating the image was to be as accurate as possible. This does not only apply to the bridge itself but also to the environment. So the landscape at the horizon, the lanterns and the island of Inchgarvie with its ruin on top are there in reality. The bridge was divided into several sections i.e. the central tower and the two towers on either side, the two suspended spans and the six cantilevers as well as the approach viaducts. The main problem was that there were no accurate detailed drawings avaialable. The main source for constructing the objects mentioned above was a reproduced blueprint depicted in the 2nd book mentioned above. However, it did not contain many readable figures. So measurements had to be taken by comparison and angles were calculated trigonometrically. In the end constructing the bridge became quite difficult due to crowding. The skysphere and the water surface were taken from the include files which came with Povray. However these were altered to give the right impression. The view is in north eastern direction and in order to hide the landscape (15 to 20 miles away) there, the horizon was kept foggy using a ground fog. The ship was placed in the image to give some idea of the size of the bridge. The ship.inc file will be included in the zip file and can be freely used as an object in your scenes. It might require a certain amount of additional work but it looks fine from a distance. By the way, I would appreciate some comments regarding the waves made by a moving ships in stills as well as animations. Some files are included in the zip file to illustrate the complexity of the task. I do not include all files as I spent one month constructing the bridge and I would like to explore other views prior to releasing the complete source files. The real problems were not associated with construction. That task was only time consuming. A real problem was getting the fog, lighting etc. properly set up to minimise post processing. However, on conversion to a jpeg image using Ulead Photoimpact 3.2 the image deteriorated dramatically and only small adjustments in contrast/brightness gave acceptable results. The image submitted is still inferior to the original image which I may offer for download on my home page (s.a.) in a few months time. The final run to get the image submitted contained over 180,000 objects.