law: Railways Act, 1989
  187. Restriction on execution against railway property. 
  (1) No rolling stock, machinery, plant, tools, fittings,
  
  materials or effects used or provided by a railway administration for the
  
  purpose of traffic on its railway, or of its stations or workshops, shall be
  
  liable to be taken in execution of any decree or order of any court or of any
  
  local authority or person having by law the power to attach or distrain
  
  property or otherwise to cause property to be taken in execution, without the
  
  previous sanction of the Central Government.
  (2) Nothing in sub-section (1) shall be construed to affect the
  
  authority of any court to attach the earnings of a railway in execution of a
  
  decree or order.