Minister of Works and Engineering the Hon. Leonard Gibbons expressed fears yesterday that a leaked letter blaming Government supervisors at the Tynes Bay Incinerator for poor management could jeopardise ongoing negotiations with its Swiss contractors.

Government and Von Roll Systems, the plant's Swiss designers and builders who are training Bermudians to operate the facility, are still negotiating a takeover date. Von Roll was scheduled to leave the Island at the end of last year.

"We want an amicable agreement,'' Mr. Gibbons said yesterday. "We don't want to discuss it in the Press.'' In a letter addressed to Works and Engineering Chief Engineer Mr. David Arden and Von Roll operators, Acting Site Manager of Von Roll Mr. Terry Barrow blamed Works and Engineering for poor management and "human error'' at the start-up of the $70 million waste plant on Saturday evening.

During the weekend start-up, Works and Engineering operations management were absent. It was discovered that the regular supervisor was on leave but no replacement had been assigned.

"No consideration appears to have been given to the shifts staffing the start-up and no prior notice given to Von Roll to cover the following shift which was known to be weak,'' wrote Mr. Barrow.

"I instructed the shift supervisor present to contact the operations engineer and inform him that unless the Works and Engineering shift cover was forthcoming, I would shut down both boilers immediately and this could then be resolved probably with more urgency on the part of Works and Engineering.'' Mr. Barrow wrote that the shift supervisor agreed to remain "under duress'' thereby preventing the shutdown.

He added that the start-up itself had been executed "very badly'', listing nine faults which he blamed on human error.

In the letter, Mr. Barrow threatened to shut down the whole facility if "either machine or human error'' put the plant in a potentially dangerous situation.

"The Ministry of Works and Engineering should be in no doubt as to my intention whilst I am acting site manager. My primary concern must be for the safe operation of this facility,'' he wrote.

Yesterday Mr. Gibbons admitted the start-up at the weekend could have been better handled. But he said Bermudians who had been doing the job for just over a year were still receiving training and lacked background experience.

Asked when Government would be taking over the full operation of the plant, Mr. Gibbons replied a date would be set as soon as Government resolved "outstanding issues''.

"We are in negotiations. We continue to have staff trained. We are meeting a standard and we're pleased with how it is going,'' he said.

Mr. Gibbons added that Von Roll were "as upset as Government'' about the leak.

Mr. Barrow refused to make any comment yesterday except to say that a series of meetings between Von Roll and Works and Engineering had been slated for the near future.