Specialist tree surgeons are installing slow release chemicals to encourage the roots to grow. They will also use a crane to remove a number of the heavier limbs to prevent the tree from falling or blowing over.
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The club says the decision to sack Ken Hare was "a disappointment". He had been at Roots Hall for 27 years.
The organisation wants to preserve as many signs as possible to add to their collection of protest art.
Thousands of passengers now face delays, with Southeastern trains warning "all services" would be affected.