Expert: Veto Varma - 4/4/2007

Question
Hello,

I'm taking this Engineering class at my college and I'm required to research the cost of building a Truss bridge. I have a few questions to ask if you don't mind
What is the cost of:
-Labor(architects , workers)
-Material (steel)
-Equipment(i need more info on what kind of equipment they use plus the cost)
-permit and fees
-and Land fees(New York City)
More info on the bridge ....
-63 members length of each member  is 15.75in
-258369.3 lbs
-20 in^2
-length is 63ft
-height 13.64 ft

Its built over water and its a one lane bridge which carries trucks and cars  

Answer
Hello Helen,

Labor-
Cost of labor differs considerably with skills. Engineers may charge from $120 to $200 per hour and same with Architects. Depending on the complexity number of hour works also differs. I assume for a short span bridge Architect might have to work 100-200 hrs , engineer , only for design, ~ 150-200 hrs. There is  administrative and drafting charges. Take ~$100/hr for another 100 hrs. This is just a very rough approximation. Exact cost may very considerably depending upon the situation.

Other labor required for installation, field welding, forming and many other tasks. It is very difficult to identify them separately in a short sapce here. You have to make a spread sheet or a program and work them out. Allow for the cost of management, inspection other administrative costs.

Material: only steel may cost somewhere from $0.6/lb to $2/lb depending upon the section. Consider cost fro shoring, platforms etc. There is extra cost involved for special sections. If you are considering substructure there will be cost of piers/earthwork etc.

For other thing you asked there is no easy answer to that depending on the situation. Different types of crane may be used, welding equipment and normal daily life construction equipments and safety devices may be used. You have to look at your present drawing and find that out. I may not comment on land and permit fees at New York city, that may be available on the city web site and you can find that out.

Hope this helps.

Regards
Veto