Dear Editor,
The recent observations by Messrs Charles Sohan and Malcolm Alli as published in the Stabroek News and Kaieteur News have forced the Joint Venture of CEMCO and SRKN’gineering to respond to the assertions expressed in the newspaper releases. We regard the writers as fellow professionals whom we feel would deal with these concerns on a face-to-face basis or through professional bodies such as the Guyana Association of Professional Engineers. Had such interaction had taken place along with the competent authority, the National Drainage and Irrigation Authority (NDIA), there would be no need to have to address the inaccuracies detailed in the report.
It should be noted that the NDIA informed us that before commencement of the project, Mr Malcolm Alli was asked by the NDIA to act as an adviser to the NDIA Board, but this offer was refused.
It is worth noting that there was an independent team of engineers including international experts who reviewed the design for the project. One of the members from the independent team of engineers was retained to provide technical support to the project. Through the Ministry of Agriculture’s website on January 4, 2010, the public was also asked to review the design report, provide comments and recommendations. Upon completion of the design report, it was forwarded to the Guyana Association of Professional Engineers (GAPE) for information and comments and a response was received in April, 2010.
Our supervision contract provides for the supervision of the civil works for the construction of the Head Regulator which is a 3 door structure, an elevated 40m clear span highway bridge and an 8 door relief structure. We report directly to the NDIA and our reporting mechanism is weekly and monthly reports which cover progress, constraints, financial projections, etc. To give the impression that the Minister and NDIA are unaware of progress is a very misleading statement. We supervise based upon the terms and conditions of our contract with the Ministry of Agriculture and supervise the contractors on the terms and conditions of their signed contracts with the Ministry of Agriculture.
The civil works contracts have a start and end date. Contractors requests for extension of time are assessed and the consultant’s responsibility is to make recommendation to the client. Any unjustified period of time that the contractor takes to complete their contract is subjected to damages in accordance with the contract.
At this point in time no extensions to any of the contractors have been granted.
With respect to the high level sluice, a concern has been raised on the design of the foundation which requires 520 no 120 ft timber piles with the inference being overdesign. The next comment was that the piles were driven out of line. This statement is incorrect. The piles were driven along a straight alignment (peg grid). All piles driven have achieved the required embedment and design blow count values. We recognize however that along grid lines “S” and “T” there has been a deviation of the pile heads. The NDIA is aware of this situation which is being addressed.
If as the writers suggest that there are too many piles and that the 7 door Abary conservancy was built without bearing piles (approximately 32 miles upriver) we would wish the writers to be honest and compare those soil conditions with the location at Hope. While we agree that a piled foundation may not be necessary for such a structure in some coastal locations, we believe that to generalize and conclude that a piled foundation for the structure is not necessary in all coastal locations may not be necessarily correct. The design of the foundation of the high level sluice was based on a geotechnical investigation specific to the location of the sluice. It is our considered view that, based on the findings of the geotechnical investigation at the site location, a shallow foundation would have compromised the integrity of the structure.
It should be noted that on October 9, 2010 an article titled ‘Poor soil conditions could halt the Hope/Dochfour Project‘ appeared in the Kaieteur News where Mr Malcolm Alli had suggested that a concrete roadway supported by piles would be needed to transport soil for the embankment. Further, he noted that machinery working on the canal would sink. However, the NDIA through a carefully designed engineering process has excavated over 80% of the canal without loss of equipment.
The 10.3km canal is being undertaken as a Force Account operation with supervision by the Joint Venture. The construction of the canal is being undertaken in phases. There are 3 design profiles which have been adopted for the embankment construction.
With respect to the embankment construction, works have recently commenced in the pegasse area between the crown dam and conservancy dam.
The design here caters for the laying of geotextile and over 200m has been laid and its application approved by the technical advisor from TenCate who is currently visiting the project. To say that the consultants are contemplating how to lay the geotextile is malicious.
Also, only 36% of the Hope Canal embankments will require reinforcement with geotextile fabric.
It was also reported that part of the eastern embankment was on fire, burning uncontrollably and will probably compromise the geotextile fabric if installed. We wish to advise that the fire burnt an area east and north of the alignment of the Hope Canal eastern embankment, which is totally outside the wayleave limit of the relief channel. This section of the eastern embankment has not been constructed as yet and when constructed will comprise of wholly suitable borrow fill and geotextile fabric. In any event fire affecting this material is slim since at all times the canal would have water stored at the level of the geotextile.
It was also reported that weeds have taken up 40% of the canal waterway, and if not removed, will take over the entire waterway in 6 months time. The writers would have observed that a section of the canal downstream of the vegetation is clean, indicating that NDIA has awarded a maintenance contract for the removal of weeds from the canal for completed section of the Hope Canal.
It was reported that bush is growing profusely on the embankments and will have to be controlled by regular maintenance. The bush is currently growing on the material to be used for the construction of the embankments and will be removed during the trimming and shaping process.
With respect to the bridge, the comment that the installed pre-stress units show changes from the original design is disturbing, as none of the pre-stressed beams have been moved from the contractor’s pre-cast yard at Onverwagt. Perhaps the writer is confused about the piles lying on site which have been rejected by the consultants.
We trust that any future concerns by these experienced Guyanese engineers can be addressed through meaningful and ethical dialogue. We stand committed to this project and welcome any intervention which may be useful.
Yours faithfully,
R B Latchmansingh
Dr Krishna Narine
Consultants
CEMCO INC
JV SRKN’gineering
