US Bridges

NFSR 700 over Tunnel Brook

Fair

Grafton County, New Hampshire · No Data Entered · Structure no. 092204000016890

Built
1972
53 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
28 ft
1 main span
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

NFSR 700 over Tunnel Brook is a wood or timber stringer/multi-beam or girder carrying NFSR 700 over Tunnel Brook in Grafton County, New Hampshire. It was built in 1972, so it is 53 years old, younger than the New Hampshire average of 56.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 50 vehicles a day, projected to reach 75 by 2045. The structure is 28 ft (8.5 m) long and 16 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
CarriesNFSR 700
CrossesTunnel Brook
LocationNo Data Entered
RouteFederal Lands Road 700
CountyGrafton County
StateNew Hampshire
Coordinates44.048, -71.855
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating40.7 US tons
Inventory rating31.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length28 ft (8.5 m)
Longest span27 ft (8.2 m)
Deck width16 ft (4.9 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (—)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was NFSR 700 over Tunnel Brook built?

It was built in 1972, making it 53 years old in 2025.

What condition is NFSR 700 over Tunnel Brook in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in August 2023.

How much traffic does NFSR 700 over Tunnel Brook carry?

About 50 vehicles per day (latest count).

How long is NFSR 700 over Tunnel Brook?

The structure is 28 ft (8.5 m) long with a longest span of 27 ft (8.2 m) and a deck 16 ft wide.

Who owns NFSR 700 over Tunnel Brook?

It is owned by the U.S. Forest Service.