@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (!super.equals(obj))
			return false;
		if (!(obj instanceof DieselLocomotive))
			return false;
		DieselLocomotive other = (DieselLocomotive) obj;
		if (tankVolume != other.tankVolume)
			return false;
		return true;
	}