Buxton Pump Station construction is a failure

first_imgDear Editor,In a news article which appeared in Guyana Times on May 23, Engineer Charles Ceres during an address at the opening of the University of Guyana’s School of Entrepreneurship and Business Innovation Inaugural Conference held at the Ramada Georgetown Princess Hotel, stated that the recently constructed $240 million pump station at Buxton on the East Coast of Demerara is an “engineering failure” since too much money was spent to build it with no instrumental benefits to residents.The newly constructed pump station has not technically proven a failure as yet in its operation as its objective is to alleviate the flooding of Buxton and its environs which is yet to be proven. It seems, however, that Engineer Ceres’ grouse is that the pump station has been over-designed with a piled foundation although in his opinion the soil which was removed to grade was heavier than the structure placed on it and therefore the underlying soil layer could have supported the pump station complex handily without additional expensive piling to reinforce the foundation of the pump structure against any anticipated settlement.I presume the design engineer for this pump station had carried out a site investigation to determine the soil characteristics for its foundation design and found it to be silty clay with low shear strength at 20 foot depth as this was the soil type I had observed at this location during the years I spent building the adjoining sea defences.Silty clay soils with a high-water content have complex consolidation/settlement characteristics whose load-bearing capacities are difficult to predict and design for. Therefore, any experienced design engineer out of an abundance of caution will use piling as a foundation for structures housing machinery on this type of soil since any settlement could cause misalignment of the pump and its motor with serious consequences. Further, vibration of the machinery during operation could cause consolidation of its clay foundation resting on an RC [reinforced concrete] slab.Engineering is not an exact science and therefore education, training, experience and good judgement are important traits of a competent design engineer. Hence what has appeared as an over-design by Engineer Ceres was in reality necessary to take care of unknowns and this is not uncommon in the engineering profession.Engineers are fully aware that if structures are not designed to generally accepted standards and they fail during their warranty period, they could be fined/jailed for negligence and be barred from practicing their profession. Therefore, no engineer should take chances to prepare sloppy designs nor to cut corners to reduce costs just because they are hungry. The recent collapse of the Palmyra Monument on the Corentyne Coast clearly bears this out.Finally, Engineer Ceres informed attendees that the Buxton Pump Station was equipped with a 70.6 cubic foot/second discharge capacity pump, but he did not state at what differential head. He would have observed from the pump’s characteristics that its discharge capacity could have been greater at the same rotational speed had the differential head been reduced since the existing layout (allows for this) is wasting a lot of energy and hence incurring additional operating costs to lift flood water to a higher elevation from the drainage channel onto the foreshore.Yours truly,Charles Sohanlast_img read more