I think this is "B.H.C. GRAB No.1 Barge 1926 SR COWPEN 237" as per George's list with the bucket dredger COWPEN which was built by Ferguson Bros at Port Glasgow in 1913.

Photographer unknown

BHC Grab No 1.

101 tons, Built Blyth 1926 as Yard Number 237.

Official Number 147748.

Blyth Harbour Commission.

There's a point Paul, I have yn's 235-248 as built by Cowpen SB between 1926 and 1930 but this interrupts the Blyth DD/SB series .... did the Blyth yard fail in the recession as many did, and re-emerge temporarily under the Cowpen name?

Can answer my own question

Up to c.1926
Blyth Shipbuilding & Dry Docks Co Ltd
then
Cowpen Dry Docks & Shipbuilding Co Ltd
then from c.1930
Blyth Dry Docks & Shipbuilding Co Ltd (note reversal of earlier name)

The Yard probably changed its name a few times BUT the Yard Numbers follow through from the Start.

Yard Number's 1 to 23 are not named and the first two I have are Nos 24 and 25 which were Steam Hopper Barges for the Russian Government built in 1880.