Experiences in Consulting Engineering
by G. Hoey, Member.
At the Durrington Community Centre, 13th December, 1989.
Mr. Hoey began his career at Reyrolle, as an apprentice, and later working on switchgear and protective systems. This was followed by service in the Electrical Branch of the Royal Navy. He then accepted the advice of his mentors to “broaden his experience and employ specialists when necessary.” In 1953 he joined consultants Preece Cardew and Ryder with whom he remained until retirement 30 years later: by then the firm had become Ewbank Preece. He then described some of the projects in which he had been involved, illustrated by slides and diagrams.
Malta power station had to be built on a very restricted site involving excavation from rock and entailing the use of spanning cranes to give access where there was no space for a roadway. Initially 2 x 5 Mw sets were installed for steam conditions 400psi/450°F followed by 2 x 12 Mw (1959-66) at 600/850 with extraction at 5 p.s.i. to supply sea water distillation plants. These (1 per turbine) were rated at 1 M gals, per day. Condenser C.W. supply was also restricted, and harbour flow studies by B.H.R.A. were commissioned to avoid recirculation problems. In recent years reverse osmosis plant has been installed for water supply.
The plant at Qatar, Persian Gulf, started with 3 Mw gas turbines of the early mobile type extended with 2 x 15 Mw (600/850) steam turbines driving generators and passing out steam to distillation plants. Inadequate design change from earlier sets with lower steam conditions resulted in cylinder hogging during start-up and high rotor vibration levels only occasionally mitigated by operator skill. After modification the machines performed satisfactorily and are still in service. It was mentioned that a distillation plant needs a sea water supply about 7 x its output.
Other installations referred to included Penang Power Station, the Gozo Plant, the Benghazi and Soussa gas turbine/waste heat boiler stations. There was also a feasability study for a 400 kv interconnector, Benghazi/Tripoli (Tunis).
Operating parameters in the Middle East have traditionally been more conservative than in Europe. One reason has been difficulty in recruiting suitable staff. Also problems encounted tend to be magnified compared with similar ones in the U.K. Fouling of C.W. systems by weed can be on a massive scale calling for facility for continuous clearance of screens, twin condensers etc. Sand is an ever-present source of trouble in ventilation systems, air intakes etc. Feed water from high head deareators coupled to range systems has resulted in scab pitting of boiler tubes often due to inadequate control of oxygen ingress, but improved availability of modern plant enables unit layout to be employed. Mr. Hoey had some
(in retrospect) amusing stories to tell, including the flattening of a C.W. pipe when trying to vacuum-prime a syphon system.
A combined cycle plant with 47% efficiency overall was engineered for an American-owned chemical plant in Germany. Steam is obtained from boilers using waste heat from gas turbines and from 2 Pass-out and 2 Backpressure steam turbines. All the turbines drive electrical generators.
Mr. Hoey described the changes he had seen in the role of the consulting engineer. Formerly the consultant managed the whole of a construction project and enjoyed considerable freedom of action. He followed the rule “the client should receive what he’s paid for, and the contractor should be paid for what he’s provided.” Most contractors were British, and most contracts contained a Contract Price Adjustment clause. Advent, of a single electrical power authority in the U.K. gave consultants few opportunities here, and seriously reduced their supply of experienced, engineers. States newly created from former colonies sent their own nationals to Europe and America for training, then expected to employ them, frequently at lower salaries than of U.K. consultants, on their own projects. Thus, post-war, with British contractors facing increased competition in the Third World from Europe and America, the British consultant found himself dealing with contractors of many nationalities in the | face of intervention by highly qualified but inexperienced clients’ engineers. But the latter were learning very quickly, and our speaker foresaw a bleak future for the Electrical/Mechanical cbnsultant in the energy field. Prospects appeared brighter in civil engineering where, in addition to contract supervision, detail design work is often required.
In discussion1 many points were made on the relative status of British and Overseas (mainly American) consultants and contractors, some with a more optimistic outlook than our speaker’s. There could be scope for the smaller firm in the extensive and complex services required by most modern buildings. The very large plants required by the U.K. supply system produces engineers untrained in the techniques required in a developing country, while in Germany, for example, there are still comparatively small private supply companies providing a source of good consultants. These consultants now have frequently to compete for work themselves in situations where swingeing penalty clauses can apply. The problem arises “who is the design authority?” in the modern scene of turnkey contracts, direct client/contractors relations, etc.
The discussion could easily have gone on long after five, but was neatly rounded off by Mr. Hoey’s story of “the consultant Tom.”