Great Loop lowest unavoidable fixed bridge

Great Loop lowest unavoidable fixed bridge on Illinois Waterway / Chicago Sanitary & Ship Canalnear Lemont / Chicago area, IL; closed clearance about 19.7 ft. Lowest unavoidable Great Loop air-draft control point.

Planning awareness only: Bridge information is provided for planning awareness only. Always verify current bridge status, clearance, water levels, bridge schedules, opening restrictions, Local Notices to Mariners, bridge signage, and official charts before transit. FloatPlanWizard is not a navigation authority.

41.65500000, -88.01100000

Published Fixed bridgeRailroad bridgeAir draft concern

WaterwayIllinois Waterway / Chicago Sanitary & Ship Canal

Route SegmentRoute-wide

Route VariantAll

State / ProvinceIL

Nearest CityLemont / Chicago area

Mile MarkerMM 300.5 / 300.6

Bridge TypeFixed/swing railroad bridge (does not open)

Source Confidencemedium

Clearance And Opening Details

Vertical Clearance Closed19.70 ft

Vertical Clearance OpenNot verified

Horizontal Clearance160.00 ft

VHF ChannelNot verified

PhoneNot verified

Last Verified2026-06-08

Verify against current water level / bridge gauge before transit.

Planning Notes

Air Draft Notes: Closed/air-draft clearance: 19.7 ft. Datum/reference: USACE low operating level / flat pool; AGLCA charted value. Clearance band: Route-limiting / Critical
Opening Schedule: Does not open
Operator / Contact: Not verified
Navigation Notes: Does not open AGLCA identifies this as the lowest fixed bridge with no alternate route. Any full-loop vessel must clear this bridge or lower gear. Closed/air-draft clearance: 19.7 ft. Datum/reference: USACE low operating level / flat pool; AGLCA charted value. Clearance band: Route-limiting / Critical Does not open
Regulatory Notes: Does not open AGLCA identifies this as the lowest fixed bridge with no alternate route. Any full-loop vessel must clear this bridge or lower gear.