Bridge Inspection || Mobile Bridge Inspection Unit || Bridge Inspection with MBIU :

The main purpose of bridge inspection is to ensure the safety of bridge and enhance the bridge serviceability. lack of regular inspection/ details bridge inspection / regular maintenance, the service life of a bridge will be reduced. We could not ensure to our users about safety during movement through a bridge without proper inspection of bridge structures. During bridge inspection, we need to check all elements or components of bridge along with protection works. Bridge inspection allows static problems and engineers to identify all kinds of minor defects in bridges before they develop into major issues. In case of high elevated bridges or bridges across the river, it is difficult to inspect girders, deck, interior faces of box girders, bearings or any other structural member without help of any equipment. So, a Mobile Bridge Inspection Unit is required to inspect thoroughly all structural members. But the Mobile Bridge Inspection Unit shall be approved by the concerned government authority.

There are two types of Mobile Bridge Inspection Unit.

Bucket type Mobile Bridge Inspection Unit,
Platform type Mobile Bridge Inspection Unit.

1. Bucket Type Mobile Bridge Inspection Unit:

Picture-1: Bucket Type MBIU (Mobile Bridge Inspection Unit)

Bucket type Mobile Bridge Inspection Unit is hydraulically operated, with electric control system. In case of bucket type Mobile Bridge Inspection Unit a bucket is attached at end of the hydraulic boom.
Maximum three members/engineerings can go underside of bridge deck with the help of bucket type MBIU. This type of MBIU can be used during Detailed Bridge Inspection and Non-Destructive Test (NDT Test). Bucket-type MBIU can be opened from the road surface of a bridge as well as from an underpass road. This type of MBIU can be opened from the deck whether footpath/ high raised additional safety railing is provided or not that's no matter. Bucket Type Mobile Bridge Inspection Unit can be opened in all types of bridges even cable-stayed bridges, truss-through bridges, Bow type bridges.

2. Platform Type Mobile Bridge Inspection Unit:

Mobile Bridge Inspection Unit (MBIU Test)

Picture-2: Mobile Bridge Inspection Unit During Bridge Inspection

Platform Type Mobile Bridge Inspection Unit is also hydraulically operated with the electric control system.

Platform type MBIU unit uses for inspection and maintenance of road bridges guarantee a safe, quick, and economic system of access to those structures where setting up of scaffoldings is not feasible or it is too costly. The MBIU unit, mounted on standard trucks, takes a few minutes only to deploy from the rest position to the work position, without personnel on board. Only after launching maneuvers are over, operators are enabled to descend on board the platform through the provided protected access, and from here; they can communicate with personnel on top of the bridge deck by means of an intercom system.
Advantage:

Three folded platforms can be opened up to 10.0m below the deck.
The entire unit can move 0.90Km/hr speed in forward and backward directions without closing the opened platforms.
The overall width of the unit is 2.25m but width of single road lane is 3.5m/3.75m. Platform type MBIU can utilize to inspect the bridges without interrupting the traffic flow. Only single lane will block during a bridge inspection.
At a time maximum five members/ engineerings can go underside of the bridge with the help of platforms. The entire bridge inspection work can not be carried out by a single person. A team leader and at least two assistant bridge engineerings need to go underside for bridge inspection.
For an easy way to conduct NDT Test
Personally, I want to tell you that feel safer in Platform Type MBIU than bucket type MBIU.

Disadvantage:

The platform type MBIU cannot be opened if high raised additional safety railings are provided on the bridge.
if distance between outer face of railing to inner face of crash barrier is greater than 1.5m, Its difficult to open at footpath side of bridge.
Nowadays most roads are designed as four lanes or six-lane bases. If the footpath is present on both the outer sides, there is an opportunity to open through the median gap. The median gap for opening the Platform type MBIU should be a minimum of 2.5 m.
It can be opened only from top of the bridge but bucket type MBIU can be opened at the underpass road without interrupting the traffic flow.