While this is trucking taken to the extreme.... one has to wonder

[HysteryDiagnosis]

how many lesser versions of this sort of beast skated across the Mn. bridge in years past. The reports mentioned cracks, not "rusted through" but cracks. From my experience the only way to crack steel is to overload it, and I have to wonder how many truck may have passed over this bridge that should not have.





http://209.85.165.104/search?q=cache:IKtkD8100CgJ:www.pubs.asce.org/WWWdisplay.cgi%3F0000178+overload+truck+permits+bridges&hl=en&ct=clnk&cd=4&gl=us
Journal Paper
Abstract: All states in the United States issue special permits for nondivisible and/or divisible truck overloads exceeding the weight limit of the highway jurisdiction. This causes stress levels higher than those induced by normal truck traffic. The rationality of such overstress levels has not been documented. This paper addresses several aspects of this issue. It presents (1) a method to develop live load models including overload trucks; (2) associated reliability models for assessing structural safety of highway bridges; and (3) proposed permit-load factors for overload checking in the load and resistance factor format. It shows that the proposed overload checking procedure leads to relatively uniform reliability of bridge structures. A sensitivity analysis is also presented here to assure that possible variations of the input data used to prescribe the proposed load factors will not adversely affect bridge safety. The proposed procedure is intended to be used by engineers responsible for checking overload permits. It may be included in evaluation specifications for highway bridges.

[MadMaddie]

1. That's a good point...and especially during the reconstruction

were they truely monitoring weights of vehicles. You would think they would have a weigh station and an alternate route if the trucks were too heavy.

I also wonder about the construction trucks themselves....they had to be pretty heavy?

[HysteryDiagnosis]

3. One would imagine.... but the cumulative flexing of very heavy

vehicles over the years could have should have been enough to take its toll. I am not sure but I think once you have an overweight/overwidth permit you are good to go. I wonder just how severely truck load limits are applied, or if it is willy nilly, catch me if you can.....

[liberal N proud]

2. I know a guy that owns one of those rigs

There are only a few of them in existence. The reason for the extreme number of axles is to distribute the load.
That is much better to have on the road weight wise than the dump trucks with 3 axles moving over sized loaded across sub standard roadways.

[HysteryDiagnosis]

4. Here's a job that's probably not going to be filled for awhile.....

http://www.metrokc.gov/jobs/assets/07June/6961.htm

* Act as Project Manager on task assignments from inception to construction.
* Develop, initiate, and monitor project schedule, cost, and plan quality.
* Prepare, negotiate, and administer consultant on-call contracts for small works and CIP projects for various bridge replacement, rehabilitation, and repair projects.
* Perform complex structure designs and prepare plan details, estimates, and specifications for bridges, walls, and other roadway related structures.
* Perform complex structural analyses and studies and prepare written reports or technical memos to discuss and address the findings and recommendations.
* Function as a technical expert to supervise and provide directions and consultations to design consultants and in-house staffs.
* Perform project feasibility and constructability reviews and discuss comments on plans, specifications, and cost estimates prepared by consultants and in-house design staffs.
* Perform bridge inspections and prepare inspection result document and inventory.
* Perform bridge live load rating and assess and issue overload truck permits.
* Review and approve construction shop drawings, shoring plans, and design calculations.
* Other duties as assigned.

[TreasonousBastard]

5. This is true-- axle weight is the key,but...

one sometimes wonders about the initial engineering of some of these roads and bridges. While interstates do have minimum standards and roads are all designed with particular weight in mind, no one really keeps tabs on what's what.

[TahitiNut]

6. In the 50s, as I recall, you couldn't drive more than a mile or so before ...

... seeing 'Weight Limit" signs or truck scales. Driving cross-country on Route 66 in the early 50s, there were truck scales all along the way. Even residential streets had "weight limit" signs. AFAIK, these weight limits were enforced. Even moving vans had to shuttle household goods on smaller trucks of the street was restricted.

Nowadays, I rarely see scales or signs. Gotta love free enterprise.

[HysteryDiagnosis]

7. Alrighty then, check this out..... even though it is OOC, I am just about

sure it applies stateside.

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JBENF2000011000003000274000001&idtype=cvips&gifs=yes
Vehicular overloads are essential for economic activities, but the circulation of very heavy vehicles involves serious concerns regarding the structural safety of bridges. In most countries, the necessary permit process is time and cost consuming and the evaluation criteria sometimes do not lead to safe situations. This paper presents a new methodology for permit checking of vehicular overloads, based on an initial statistical study performed to characterize these vehicles. The method includes software that performs a simplified structural safety analysis of the bridges crossed by a vehicular overload, computing safety factors that compare code design load effects with those due to vehicular overload. The software also connects the vehicular overload database with a geographic information system representation of the highway network, allowing for the definition of several functionalities that support the permit decision. This new methodology allows for prompt, economical, and safe decision making on permit checking of vehicular overloads and is presently applied by the Portuguese national major expressway authority.

[B Calm]

8. These types of trucks come with a police escort. When they get

to a bridge/overpass, all traffic is stopped and the only vehicle on the bridge is the truck. I wouldn't think one truck would weigh as much as bumper to bumper traffic.

[cynatnite]

10. A standard semi and trailer can't go over 80,000 lbs...

overweight loads...well, those can go pretty high. 200,000 lbs isn't unusual.

[cynatnite]

9. I've dispatched trucks and my husband is a trucker...

When it comes to overweight or oversized loads the DOT is very strict about those. Depending on the kinds of loads they usually have to follow a very precise route, check in with the scales, can only go so fast, drive during certain times of the day, no weekend driving and no night time driving...unless it's a FEMA truck that damn near runs you off the road (happened to me).

I've dispatched oversized and overweight loads before and I can tell you for a fact that to get them legal and within the DOT safety guidelines takes a lot of money, time and effort. The scales are on average at major highways leading into and out of each state. With oversized and overweight loads permits are required for each individual state. Many times pilot cars are required for these big loads.

Those kinds of loads such as the one pictured above is an exception. The requirements for those loads are stricter and much harder to drive. Their speeds are usually much slower.

This tragedy was not the fault of truck drivers no matter what they drive.

[HysteryDiagnosis]

11. Truck drivers were never mentioned, until now. n/t