D.C. Code § 5-404

The Fire Department of the District of Columbia shall be composed of and operated upon a 2-platoon system and the personnel thereof shall consist of 1 Fire Chief; such number of Deputy Fire Chiefs, all of whom shall have had at least 5 years of experience in some regularly organized municipal fire department, and battalion fire chiefs as said Mayor of the District of Columbia may deem necessary from time to time within the appropriations made by Congress; 1 fire marshal; such number of deputy fire marshals, inspectors, and clerks as said Mayor may deem necessary from time to time within the appropriations made by Congress; such number of captains, lieutenants, and sergeants as said Mayor may deem necessary from time to time within the appropriations made by Congress; 1 superintendent of machinery; and such number of assistant superintendents of machinery, pilots, marine engineers, assistant marine engineers, marine firemen, privates of class 6, privates of class 5, privates of class 4, privates of class 3, privates of class 2, privates of class 1, hostlers, and laborers as said Mayor may deem necessary from time to time within the appropriations made by Congress; provided, that the Fire Chief of the Fire Department of the District of Columbia shall have the right to call for and obtain the services of any veterinary surgeon employed by the District who at the time shall not be engaged in a more emergent veterinary service for the District; provided further, that the police surgeons of said District are required to attend, without charge, the members of the Fire Department of said District, and examine all applicants for appointment to, promotion in, and retirement from said Fire Department.