Distance: 11.7 km (5.0 DOC hours) - Tramping track - Easy-moderate terrain
Altitude: 499m to 686m. Gain: 449m. Loss: 273m . Gradient: 4 deg (Gentle)
Skills:

Tramping track (4/9)
Cut, marked tramping track: natural, rough ground surface

Primary, mapped (1/5)
Formal route, on maps, principal access to hut or along range / catchment

Gentle (difficulty: 2/5)
Gentle slopes

Easy-moderate (difficulty: 2/5)
Tussock / river-gravel / open bush / cut track

Unknown (difficulty: 0/7)
Not specified

None (difficulty: 1/6)
No unbridged river crossings

Unknown (difficulty: 0/7)
Not specified

@admin - merged into duplicate route
Being part of the Travers-Sabine loop, the track is well defined.
The only significant climb/descent (approx 100m) is upstream of the fixed bridge, 2km from Sabine Hut. Otherwise, it's an easy tramp beside the Sabine River, mostly in the forest but occasionally traversing grassy flats (suitable for camping if needed).

To gain access to West Sabine Hut, the new (2013) swing bridge is just upstream of the hut.

Note: Described in the reverse direction to your journey

Cross to the TL on the swing bridge, just upstream of the hut, and follow the well defined track downstream. There are a few clearings suitable for camping but the track, never very far from the river, is mostly under the canopy. There is only one climb of note, shortly before the bridge which crosses to the TR - just a km from Sabine Hut.