Con­struct a sec­tor plate

Dave Low­ery ex­plains how he har­nessed the po­ten­tial of this sim­ple space-sav­ing de­vice.

Model Rail (UK) - - Contents -

Dave Low­ery and Peter Mar­riott har­ness the po­ten­tial of this sim­ple space-sav­ing de­vice on their lay­outs.

Most of us try to cram as much as pos­si­ble into our lay­out plans, and this is when space-sav­ing so­lu­tions can come in handy. One of the sim­plest op­tions is a sec­tor plate. A sec­tor plate is a piv­ot­ing sec­tion of track that al­lows trains to run from one line onto an­other with­out the need for points. Act­ing in a sim­i­lar way to a turntable, many di­verg­ing routes can be laid to per­mit trains to ac­cess a fan of stor­age sid­ings or to re-emerge onto the scenic sec­tion on a par­al­lel line. Sec­tor plates can also act as one end of a run-round loop, al­low­ing a lo­co­mo­tive to change tracks off-stage. They can be built to al­most any length, to help shunt a lo­co­mo­tive alone, or en­tire trains. So use­ful is the idea that I built a whole lay­out around a sec­tor plate. ‘Bevet’ is a com­pact ‘P4’ gauge lay­out, built in the mid-1980s and based on the Lon­don & North Western around the turn of the 20th cen­tury. In ‘front of house’ is the scenic lay­out, with sta­tion, goods yard and small engine shed. Two lines – the main run­ning line and the route into the cat­tle dock – run un­der an over­bridge and out of view. The sec­tor plate is ro­tated to line up with ei­ther of these two lines while the train leaves the scenic sec­tion. The plate is then moved and the train re­versed onto one of the hid­den stor­age tracks be­hind the lay­out, or onto the ad­ja­cent scenic line dur­ing shunt­ing op­er­a­tions. The process is sim­ply re­versed to al­low

trains to move from stor­age onto the lay­out in the op­po­site di­rec­tion. The sec­tor plate is sim­ply a length of ply­wood, about 2ft in length, se­cured to a piv­ot­ing point a few inches from the outer end by a stan­dard wood screw. The screw is tight­ened only enough to keep the wood in place, while be­ing loose enough to al­low the sec­tor plate to ro­tate on this axis. A means of align­ing the tracks is es­sen­tial for re­li­able op­er­a­tion. One sim­ple so­lu­tion is a small brass bolt and socket that will lock into place and hold the plate in po­si­tion while the trains run back and forth.

EN­SUR­ING AC­CU­RACY

As my lay­out is built to ‘P4’ stan­dards, the tol­er­ances of rails and wheels are finer, and the align­ment, there­fore, must be as ac­cu­rate as pos­si­ble. My so­lu­tion was to place an etched brass W-iron unit from a wagon kit un­der the end of the sec­tor plate, fit­ted with a set of brass bear­ings and a set of small wheels. Within the sec­tor plate’s well are strate­gi­cally placed pairs of phos­phor-bronze strip, fixed se­curely to the wood base. As the sec­tor plate moves, the wheels drop into the groove be­tween the metal strips and align with the tracks above per­fectly. Fur­ther­more, to help smooth tran­si­tion across the gap, the ends of the rails flare very slightly out­wards on the sec­tor plate and the run­ning lines. As for the wiring, all you need to do is add a power feed to each rail on the sec­tor plate. Only if the plate re­volves more than 180º do you need to worry about po­lar­ity re­ver­sal, as you would with a turntable. Fi­nally, a piece of black card is fixed to the side of the sec­tor plate so that it blocks off the view through the bridge from the front as­pect as the plate is moved. Thus, the hap­pen­ings ‘off-stage’ are hid­den from view. The prin­ci­ple is a sim­ple one and the idea has been in use for many years. How­ever, it’s still very ef­fec­tive and of­fers plenty of op­er­a­tional po­ten­tial for space­con­scious mod­ellers.

Sec­tor plates can be made to al­most any length. Smaller plates can han­dle lo­co­mo­tives only, re­plac­ing the need for points and a head­shunt in a run-round loop.

The sec­tor plate feeds the scenic lay­out by ro­tat­ing be­tween three stor­age sid­ings at the rear. Note how the con­trol panel is fixed above the stor­age sid­ings to max­imise space.

A set of brass W-irons and a set of wheels is se­cured to the bot­tom of the sec­tor plate, sup­port­ing the track as the plate piv­ots on its fixed axis.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.