As mentioned in previous posts I have decided to use the Brian Morgan turnout operating units for all the pointwork on Barrow Road. Brian has produced some superb etches for B & C switches in P4 which can be obtained from the Scalefour Stores. His main interest is the GWR and whilst the original units were designed specifically for Great Western loose heeled switches he has also produced the other version for non GW railway turnouts.
The TOU etches, one for the standard B, C switch, the other showing one half of the double slip. Brian also does a single slip.
Here is a close up of the underside of the TOU for Barrow Road north exit. It shows the base plate, tufnol operating bar in it's guide, and the operating crank on it's etched mount. The crank gives 12mm clearance under the board but Brian also provides a 15mm version as an extra. I have chosen to replace the 8BA crank nut and bolt with M2.5 as this allows the use of a M2.5 nyloc [ to be added] rather than fixing with loctite or nail varnish.
A close up of the top side of the unit
The north exit unit
An overall view of the underside of the north exit TOU. The strips of 6mm wide black card have been added to minimise the contact surface for gluing to the baseboard and assists future removal of trackwork without damage. Credit for this idea goes to group a member Graham Turner who, unknown to me, incorporated it in the original build of Brinkley. It is well proven as some of the track on this layout required relaying and was removed without damage and relayed. The advantage is the card can be cut to remove trackwork.
Here is the Brian Morgan etched jig showing an tufnol operating unit with 10BA bolt and brass tube inserts for the switch droppers
Having built the north exit unit I found that the spacing of the Brian Morgan jig at 16.5mm meant that the spacing between the switch and stock rail looked too wide. Brian gives the required spacing as 1.45mm but I think 1mm looks better. Discussion with others, including Morgan Gilbert, resulted in a new specification of a 17.5mm spacing a a new drilling jig - thanks Morgan.
Here is Morgan's new jig with the 17.5mm centres for the droppers. The centre hole is for the 10BA bolt for the operating crank.