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caw123
Oct 1, 2003, 5:33 PM
Looking through the diagram I noticed many structures such as this are listed as Towers, and most have 'truss' as a secondary building type, whats the point of listing 2 structural types, Tower and Truss when you could have just Truss Tower as a building type?
http://www.skyscraperpage.com/cities/?buildingID=553&drawingID=17455

IMO all these should be changed to just Truss Tower:

http://www.skyscraperpage.com/cities/?buildingID=553
http://www.skyscraperpage.com/cities/?buildingID=8568
http://www.skyscraperpage.com/cities/?buildingID=2723
http://www.skyscraperpage.com/cities/?buildingID=6749
http://www.skyscraperpage.com/cities/?buildingID=1715
http://www.skyscraperpage.com/cities/?buildingID=2686

Or should they be left as they are?

Kelvin
Oct 1, 2003, 7:32 PM
It’s not wrong to have them individually noted, but you are right in that they are more appropriately defined as “Truss Tower”. The category “Tower” still needs to be distinct as there many types (monolithic, Vierendeel, guyed, etc.) and the category “Truss” also has many possible variations (horizontal, vertical, Warren, Howe, etc.).

What does concern me is the use of Sea Level elevations in the height column (eg. 624.6m Antenna w.r.t. Sea Level). Having this data as part of the height information will potentially allow it to become incorrectly ranked! Also, there is a base width dimension in with the height data. I would recommend that only local heights be placed in the height columns and all other data be placed in the Description field as text.

Dylan Leblanc
Oct 1, 2003, 9:13 PM
Yes, all those should be changed to 'truss tower', which I have done.

I found two entries witth non-negative sea levels, and fixed em

Kelvin
Oct 2, 2003, 12:34 AM
Well, like we discussed before; a sea-level value will almost always be negative for our purposes but it could be positive. We want to measure the relative change in elevation from the base of the give structure to the MSL. Assuming that measuring upwards is positive, then downwards is negative. However, if the structure's base were to be below MSL, then we would show a positive value. I can think of a few instances where this might occur, namely: around the Dead Sea, in Holland, or a submerged/marine/offshore structure.

I'm just thinking that showing tip elevations as part of the official height list is wrong because we are showing heights relative to base only. While elevations and heights may appear to be the same thing, they are not. If they do get mixed together, it will lead to incorrect "pinnacle" rankings.

all that is really needed is a seperate data-field devoted specifically for recording the difference between our local datum (base of structure) and the global datum (mean sea level, MSL). With that information, the tip elevation can be calculated if need be by adding the structure Height to it's base elevation w.r.t. MSL.

Just a thougt ;)

M. Klatt
Oct 2, 2003, 12:46 AM
i really don't get it ....

MSL? Why should we add something like that????

just as Example:

This "Sender Ochsenkopf" is a 166 m Tower on a 1023 m Hill. So a "total Height above MSL" would be 1189m ...

http://www.br-online.de/br-intern/technik/img/ochsenkopf.jpg

i would laugh about a Diagram, when this Tower is rated as "higher" than the CN Tower ....

( btw - this is one point i'm missing this one: :tp: )) :laugh:

Kelvin
Oct 2, 2003, 1:00 AM
That is the point, it's not the height - but rather the elevation. Yes, it's tip elevation is 1189m, but it's height is 166m.

You demonstrated the potential conflict perfectly Marco. If someone had entered the relative elevation as one of the user defined heights, then it would appear that this structure would be very tall (1023m), almost twice the height of the CN Tower.

The idea of having a seperate MSL elevation box would not be for height ranking, but rather for information purposes only. The Mean Sea Level elevation would never be used to determine a pinnacle height.