Cable-Stayed Bridges - Ting Kau Bridge (2)

A view of the Ting Kau Bridge (part of Route 3) from the deck of the Tsing Ma Suspension Bridge (part of the link from the mainland to Lantau Island).
The Happy Pontist commented that the very long (longitudinal) cables aren't for providing stability from wind loads (as I suggested) but to stiffen the central tower. He directs us to Michel Virlogeux's paper, Bridges with Multiple Cable-Stayed Spans, published by the International Association for Bridge and Structural Engineering (IABSE) in 2001. I haven't read this paper (it costs $28 to download) but I believe the long cables make the central tower more resistant to longitudinal movement. A three span cable-stayed bridge uses the pier at each end as a tower anchor. The central tower of a four-span cable-stayed bridge is between long flexible spans that don't provide sufficient longitudinal restraint and require long cables to anchor it to the adjacent towers.
Although the Happy Pontist doesn't mention it, I believe the transverse cables (arranged like the cables around a ship's mast) make the three towers more resistant to transverse movement.

Cable-Stayed Bridges - Ting Kau Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Cable-Stayed Bridges - Ting Kau Bridge

The Ting Kau Bridge is a unusual cable-stayed structure across Rambler Channel in Hong Kong, China. It has three single-legged towers (560 ft, 640 ft, 520 ft) that are stabilized with transverse cables above and below the deck. Moreover, the central tower is supported by extremely long (1530 ft) cables extending to the far towers. The extra cables are to help resist the strong winds and typhoon loads that blow through the channel.

This bridge also carries the highest daily traffic in Hong Kong and the largest number of container trucks between Mainland China and the container port in Hong Kong. It is a six lane bridge built in 1988 with a total length of 3864 ft and with main spans of 1470 ft and 1560 ft.

Driving across the bridge, one is struck by the hundreds of container ships waiting to enter the port. Also, by the distinctive yellow on the steel anchorages at the top of the towers and on the steel girder superstructure.

Cable-Stayed Bridges - Ting Kau Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Cable-Stayed Bridges - Flößerbrücke

This eccentrically-supported, single-tower, cable-stayed bridge is across the Main River in Frankfurt Germany. It's name means raft (or pontoon) because it replaced a floating bridge that was built in the 1960s. The current bridge, designed by the architect Egon Jux, was not to everyone's taste and it remains the only reinforced concrete cable-stayed bridge in Frankfurt.

The two pylons, each lifting a single cable on a saddle, supports the superstructure at midspan. The tower does not continue below the deck (similar to the Millau Viaduct) and the prestressed box girder superstructure is supported by bearings and a pier wall.

The bridge is 725 ft long with a main span of 350 ft.  The tower is 70 ft high and the deck has a variable width between 70 to 114 ft. More information about this bridge (in German) is available from Wikipedia.

Cable-Stayed Bridges - Flößerbrücke by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.