1.SELECTING THE STEELWORK SUB-CONTRACTOR

1.1 Pre-selection

The following comments apply to major steelwork contracts. For lesser

contracts site management can select those items for checking appropriate to the nature and magnitude of the contract. If appointed by your company, the sub-contractor's commercial standing and professional competence should have been vetted as a matter of course at tendering stage but often the subcontractor is appointed by others. It is desirable in both cases that site management and/or competent Company representatives, before placing the sub-contract, check what jobs have been done by the proposed subcontractor. Find out whether they had problems with fabrication, deliveries, erection etc.

    An increasing number of constructional steelwork contractors are

becoming members of the British Constructional Steelwork Quality

Assurance Certification Scheme (BCSQA).

    The steelwork sub-contractor's quality management system has been subject to assessment by independent assessors with an in-depth knowledge of the industry and that the performance of the company is continually under surveillance by visits to its works and on site.

 

1.2 Assessment

It is normally a condition of sub-contracts that Your Company

representatives shall have free access to the sub-contractor's Works for

inspection during the progress of the contract. If appointed by others check the Conditions of Contract to ascertain whether or not this requirement has been included. If not, take steps to obtain proper inspection facilities. Visit the Works, get to know the layout and the people involved and check their methods of quality control and traceability. All bare steel (unpainted)supplied to the fabricator will have been cut slightly over length (except for the smaller sections) and will have the grade stamped and colour coded for easy recognition on one end. This also applies to plate when the grade and colour code is generally in one corner.

    Check how the sub-contractor keeps track of the member. In fabrication, the stamped mark and the colour coding often disappear in cutting, welding, grit blasting etc. Similarly the plate -if they cut off the stamped corner to make a stiffener, do they re-stamp the remaining plate so that it can be identified for future use?

    Both mild and high tensile steels can be used in the same design. Check how the fabricator ensures that these are identified correctly in the works to prevent transposition.

     The method of 'traceability' must make it possible for a piece of

steelwork to be traced back to a Material Test Certificate for a specific

casting of steel. These are required by  your company as a matter of course and

are to be distributed as required by the contract documents.

Visit the drawing/design office. Check the fabrication drawings:

• are there sufficient dimensions?

• are the sizes of all welds and welding techniques given?

• are the holing sizes and dimensions shown?

• is the steel grade shown?

• are the grades of bolts given?

• is the paint treatment and preparation shown?

• have they been checked and signed?

Check the method of cross referencing the fabrication and the general

arrangement drawings. The number of drawings on a big job may run into

many hundreds and easy cross referencing is essential.

   Visit the template loft (if there is one). This will give a good idea of

the accuracy they work to with regard to the connections, holing etc. There

may be a difference between the serial size and actual size of a member;

the fabricator should be working to the actual size. Are the rolling margins

for section and straightness checked by the fabricator.

   Visit the welding shop. Ask the fabricator for a copy of his welding

procedure and check that the welder is following this. In large plated girders,

are they following a welding consultant's recommendations. Are the welders

coded? If so, see certificates. Visit the cutting shop, plating shop, drilling

shop, grit blasting and painting shops.

    Generally ask about deliveries. Will they be by road, rail or a

combination of both? If by road, are vehicles in-house or sub-contracted?

What is the size of vehicles and maximum load?

Ask for copies of Mill Certificates, Procedure Qualification and Welders'

Certificates, and welding test results by an independent laboratory.

    On a works visit one can gain an overall impression of the subcontractor.

He must be able to satisfy you against the specified requirements.

Until he can do this he should not be allowed to proceed.

NB: The sub-contractor is normally made contractually responsible for

arranging all necessary traffic movements with the Police and Statutory

Authorities and made responsible for making good any damage by his vehicle

to public highways.

(b) Tour Company provides for the safe custody of the sub-contractor's

materials on site and assumes responsibility for security of same.

Where in the sub-contractor's opinion dry covered storage is

required, this is provided within the site perimeter. Usually the

sub-contractor states the area of covered storage he requires.

(c) All builder's work is complete to enable erection to start

immediately for completion in one site visit during normal working hours.

(d) Your Company provides for the maintenance of all safety, health and

welfare facilities, in accordance with statute or Statutory

Regulations, for the steelwork sub-contractor and his work force

free of charge. No liability will be accepted by the steelwork subcontractor

for any non-compliance with these regulations.

(e) Where mains electricity is laid to site, Your Company may provide

the necessary electrical power on site, usually 110 volt AC for general use.

Check with the steelwork sub-contractor what powerpoints and

distribution he will require in addition.

(f) There are no overhead obstructions, all electrical cables and other

services have been removed to enable site works to proceed unhindered.

Existing or new underground services need protection

against loads from cranes, vehicles or stacked materials.

1.4 Necessary action by site management

It is important that site management deals with the points in 1.2 with the

steelwork sub-contractor before appointment at tendering stage. Failure to

meet any agreed conditions by the right time could seriously delay the job.

Operational planning should take full account of these points.