How on earth would a planner handle EOT programme of a $150m construction project that has been on hold due to Force majeure for more than 5 years?

Claim for EOT & cost due to force majeure depends on contract condions and governing laws. Normally no clause is defined for force majeure in the contract documents even it was not defined in FIDIC old editions. 

The definition of force majeure provided in the new FIDIC form at clause 19 is widely drawn. Clause 19.1 defines a force majeure event as one:

• which is beyond a Party's control,
• which such Party could not reasonably have provided against before entering into the Contract,
• which, having arisen, such Party could not reasonably have avoided or overcome, and
• which is not substantially attributable to the other Party.

Force Majeure may include, but is not limited to, exceptional events or circumstances of the kind listed below, so long as conditions (a) to (d) above are satisfied:

• munitions of war, explosive materials, ionising radiation or contamination by radioactivity, except as may be attributable to the Contractor's use of such munitions, explosives, radiation or radioactivity, and
• natural catastrophes such as earthquake, hurricane, typhoon or volcanic activity.
• war, hostilities (whether war be declared or not), invasion, act of foreign enemies,
• rebellion, terrorism, revolution, insurrection, military or usurped power, or civil war,  
• riot, commotion, disorder, strike or lockout by persons other than the Contractor's Personnel and other employees of the Contractor and Sub-Contractors,
• munitions of war, explosive materials, ionising radiation or contamination by radioactivity, except as may be attributable to the Contractor's use of such munitions, explosives, radiation or radioactivity, and
• natural catastrophes such as earthquake, hurricane, typhoon or volcanic activity.

The broad definition of force majeure to be found here, and it should be remembered that the examples listed above are examples and not an exhaustive list, reflects the basic premise of a force majeure clause, namely that it serves to exempt a party from performance on occurrence of a false majeure event.

The plannig engineer from contractor should submit EOT claim by taking hold on period due to force majeure as a delay event using suitable delay analysis method. Most likely the client will have no objection in approving EOT claim but may or may not will have objection on cost claim of prolongation period and dmages due to force majeure depending upon contract conditions and governing laws either local or international.

Conclusion:

Contractor will try to claim maximum (Time & Cost) and negotiate till mutual acceptance.