49 C.F.R. § 231.28
The specifications of § 231.27 shall apply except as to the following:
(2) Dimensions.
(e) Existing box and other house cars with roof hatches. Box and other house cars with roof hatches built on or before April 1, 1966, or under construction prior thereto and placed in service before October 1, 1966, shall be deemed equipped as nearly as possible within the intent of § 231.1 and of this section when: Equipped as specified in § 231.1, except (1) the side ladder treads above the fourth tread from bottom of side ladder near “A” end of car and roof handhold over the side ladder near “A” end shall be removed; (2) and (1) end platform handhold shall be provided on each end of car as specified in § 231.27(i); and when handbrake is operated near roof of car a brake step shall be provided as specified by § 231.1 or when handbrake is operated from approximate level of top of end sill the roof handhold over side ladder near “B” end and treads above the fourth tread from bottom of side ladder near “B” end shall be removed and a brake step as specified in § 231.1 shall be used with top of tread surface level with or not more than four (4) inches below adjacent end handhold.
(Secs. 2, 4, and 6, 27 Stat. 531, as amended; secs, 1 and 3, 32 Stat. 943, as amended; sec. 6(e) and (f), 80 Stat. 939 (45 U.S.C. 2, 4, 6, 8, and 10, 11-16 and 49 U.S.C. 103(c)(1))
[33 FR 19663, Dec. 25, 1968, as amended at 49 FR 26745, June 29, 1984]