PAS: Hoosac Tunnel Bends (but doesn’t break) Following Wet Christmas

REBUILT TUNNEL WITHSTANDS HEAVY RAIN AND SNOWMELT, BUT WEST PORTAL EXTERNAL RETAINING WALL LETS GO. SERVICE RESTORED NEXT DAY.

26.December, North Adams MA – At 08:45 hours during a daily track inspection, the track outside of the west portal of the Hoosac Tunnel was discovered to be blocked by mud and fallen trees. The deposited material dammed-up natural water drainage from the tunnel, submersing the tracks some tens of yards into the tunnel’s west end. It is unknown when the landslide occurred, following the clear passage of an overnight train. The day’s traffic was immediately embargoed. Trains affected were PAS 16R, PAS RJED, PAS EDRJ, and PAS 23K. Some trains did make their revised schedule that night.

Hoosac "carwash"
Rerouted after the Hoosac February collapse, Trout Brook is adding pressure behind the retaining wall. In this 24.December photo, the retaining wall is already overflowing. The next day brought heavy Christmas-day rain, and by Saturday the old wall buckled under the weighty mud {photo Jerry Kelley, Hoosac Tunnel Then and Now}.

Hello, Wall

An original (1875) stone retaining wall that runs along the north side of the track alignment exiting the tunnel gave way under the weight and instability of saturated ground, resulting from a two-inch Christmas rainfall, and its melting effect on over a foot of residual snow deposited a week earlier by Winter Storm Gail. The entire region was saturated.

 

Deja vu all over again?

In February, the Hoosac Tunnel suffered an internal collapse, caused by seepage and erosion from the Tunnel Brook, which flowed from the north and over the tunnel’s west end, hundreds of feet up the mountain. The cave-in caused a 53-day closure. Reopened in April, The repaired and upgraded tunnel reopened in April. Tunnel Brook was rerouted away from the tunnel, by running it farther along the north side of the ROW, before crossing south beneath the trackbed, well outside of the portal.

North Adams MA – The Tunnel Brook knocks the Hoosac Tunnel to its knees after a soggy Christmas, but the old bore quickly got back up, swinging. Following the February tunnel collapse and 53-day closure, the southwest-flowing Tunnel Brook was rerouted to cross the ROW well outside the tunnel. Running now along the north side of the track, the additional water places new pressure on the stacked-stone retaining wall that has held the mountain off the open tracks since 1875. While a lot of crocodile tears were shed on social media over the slide, the tunnel was reopened by nighttime, with a 10.mph speed restriction between CPF 421 and the West Portal {PAR EVP C. Scarano}.