43 CFR §3481.4-2

1. (a)Movement, failure, or repair of major equipment, such as draglines or longwalls; overburden removal; adverse weather; employee absences;
2. (b)Inability to sever coal due to orders issued by governmental authorities for cessation or relocation of the coal severance operations; and
3. (c)Inability to sell or distribute coal severed from the lease or LMU out of or away from the lease or LMU.