Marine Asset Cathodic Protection & Under Water Management Services for the Public Transport Authority

1. Background

The Civil Branch of the Public Transport Authority (PTA) is seeking a highly experienced and capable organisation to provide marine diving and vessel management solutions to assist with the maintenance of its underwater bridge structures.

As the PTA is responsible for maintaining the safety and function of these bridges, as well as the rail reserve, tunnels, and associated infrastructure, the organisation will also be required to provide ongoing bridge infrastructure cathodic protection services, conduct maintenance and inspection, and provide scour control around rail bridges. The Fremantle Rail Bridge is the only structure with cathodic protection equipment installed. PTA may expand the number of structures requiring these services to include others within the metropolitan and/or regional areas in future.

Previously these services have been covered under two separate contracts;

• PTA2015029 – Tender – The Provision of Bridge Infrastructure Cathodic Protection Services for The Public Transport Authority, and
• PTA170771 – Quote – Marine Divers and Vessel Services

Upon review of these contracts, it was determined it would be more beneficial to the PTA to merge these two contracts into one, due to the marine diving portion is better suited to be managed by the successful Tenderer responsible for the bridge works.

1. Scope of Services and Specification

The successful Tenderer will be required to provide the following services:

Standard Services

a) Impressed Current Cathodic Protection (ICCP) once every six months inspection & report on PTA Bridge structures. Appendix A includes details of the types and frequency of maintenance required.

b) ICCP Refurbishment & maintenance of existing systems on PTA Bridge Structures/Assets.

c) Concrete condition/integrity assessment auditing & reporting.

d) Concrete refurbishment to reinstate PTA Structure/Asset integrity.

e) Minor repair and maintenance to the protective coating systems on PTA Structures/Assets as required for small tor the purpose of clarity, the Contractor is not responsible for the significant painting of the entire bridge structure. In the event that major painting is required, the work would be procured through a separate competitive quote/tender process.

f) Provision of ROV (Remotely Operated Vehicle) and operator for annual assessment auditing & reporting of immersed steel support piles of PTA Structures/Assets. The ROV must be capable of capturing High-Definition video images.

g) Spotter/rescue vessel & operators for Bridge work over marine locations as required.

h) Provision of condition assessments as per clauses 3.2.4 to 3.2.14.8 of AS 5100.8:2017 Bridge design - Rehabilitation and strengthening of existing bridges.

i) Provision of CP assessment and maintenance. As per Clause 3.3 & Appendix B of 5100.8:2017 Bridge design - Rehabilitation and strengthening of existing bridges.

The only access to the underside of the bridge is by boat. Scaffolding will be required for all work undertaken at height.

Underwater Services

The successful Tenderer may be required to provide the following services:

a) In any instances where the ROV cannot precisely determine a suspect underwater issue, the Contractor shall utilise underwater divers when required. The Contractor will define the scope of their role, which typically includes visual inspection, collection of samples etc.

b) Simple repairs/remedies and all other measures supporting a solution.

c) Diving services for inspection, including high-pressure cleaning of support piles.

d) Provision of Non-Destructive Testing (NDT) Ultrasonic Thickness Testing.

e) Provision of wrapping/sleeving services to steel/timber support piles based on supplied specifications.

f) Provision of Scour condition assessment, maintenance, and monitoring. General overview provided within PTA document 8803-450-001 - Guideline - Underwater Marine - Hydrodynamic Scour Prevention and Management

Deliverable

• Surface and subsurface bed material of waterway including the vegetation and accumulation of the debris for each all the components of the bridge; for the approach section and contracted section

• Foundation depth and foundation type

• Pier dimension and orientation

• Abutment - Location of abutments relative to the main channel

• Depth, velocity, and alignment of flow through the constriction/bridge components

• slope and alignment of the natural stream including the depth of the main waterway channel bed depicting the flow direction, flow paths, flow contraction and expansion through bridge

In performing any of the activities as nominated above, the Diving Contractor shall be responsible for providing all manpower, diving support vessels, tools and equipment necessary to execute the works. All diving works must comply with AS/NZS: 2299.1.2015 Occupational Diving Operations.

Prior to inspection of piles, the Contractor will require a marine vessel management plan approved by PTA and the Fremantle Port Authority.