Section 6 Acceptance testing of pontoons, bridges, ramps and walkways

6.1.1  Hose testing. Any watertight doors, bulkheads, tunnels or weathertight deck closures are to be pressure hose tested, with a hose supply pressure of at least 0,2 MPa, from a maximum distance of 1,5 m, to the Surveyor's satisfaction.

6.1.2  Pressure testing. Water ballast tanks are to be pressure tested to a 2,40 m head above the highest point of the tank, excluding hatchway, or to the top of the overflow, whichever is the greater.

6.1.3  Leak testing. Leak testing is required on fillet weld connections on tank boundaries. This test is also required on erection welds on tank boundaries except for welds made by automatic processes. Selected locations of automatic erection welds and pre-erection manual or automatic welds may be required to be similarly tested at the discretion of the Surveyor taking account of the quality control procedures operating in the yard. This test is carried out by applying a soapy water solution to the weld being tested while the tank is subjected to an air pressure of 0,015 MPa. It is recommended that, with a minimum number of personnel in the vicinity of the tank, the air pressure in the tank is raised to 0,02 MPa and kept at this level for about one hour to reach a stabilized state, and then lowered to the test pressure prior to inspection. Leak testing is to be carried out before a protective coating is applied.

6.1.4 When a protective coating is to be applied to the internal structure of a tank, the water test may take place after the application of the coating, provided that the structure is carefully examined to ensure that welding and structural stiffening are completed prior to the application of the coating, excluding prefabrication primers. The cause of any discolouration or disturbance of the coating is to be ascertained and any deficiencies repaired.

6.1.5 Pressure testing may be carried out afloat where testing using water cannot be accommodated in dry-dock or on the building site. The testing afloat is to be carried out by separately filling each tank and cofferdam to the test head given in Pt 3, Ch 1, 6.1 Pontoons 6.1.2.

6.1.6 Alternative proposals for testing will be considered.

6.2.1 Each bridge or walkway span and every ramp span is to be proof tested in its working position by applying appropriate test loads after installation, and following any major repair, renewal or modification to help verify compliance of the structure and its support arrangements with the Rule requirements. Testing is to be carried out throughout high and low tide conditions to allow for the dynamic effects of tidal movement. It should be noted that testing does have some limitations for verifying structural integrity and will not verify fatigue strength.

6.2.2 The magnitude of the proof test load, T, is to be based on the applied design load, W, in tonnes, of the bridge, ramp or walkway section derived from the design UDL x working area, or in the case of ramps and bridges the maximum vehicle load or SWL, as follows:

A concentrated load equivalent to a UDL, or vice versa, may be used where appropriate.

6.2.3 Additionally, bridges, ramps and walkways that are raised or lowered when unloaded are to be proof tested to the satisfaction of the Surveyor after installation and after major repair, renewal or alteration as follows:

1. The brake or other mechanism, if fitted, is to hold the bridge, ramp or walkway in its most unfavourable position whilst carrying an additional test load equal to 25 per cent of its self weight. The test load is to be evenly distributed over the working surface where this is practicable.

2. Any part of the linkspan which may be mechanically hoisted or lowered is also to be operated through at least one complete operating cycle.

6.2.4 Alternative proposals for testing will be considered.