Pearl Modifications


 From an article in the Maxitrak News of Winter 1994 - By Mr B M Watt.



As a new member of the Maxitrak Club living far from the "seat of knowledge", I have just completed my 71/4" gauge Pearl, "Nutmeg" and must apologise to Andy for my frequent phonecalls. There are no other kindred souls up here in Inverness to whom I could have turned.


I recently completed a 4 hr running session on Bob Smith's Comrie Railway, although my normal home track is the Ness Islands, Inverness, on which I am granted running access. The Comrie outing was very successful with nothing shaking loose, but due to the damp weather and a rather to high seating position on my bogie driving wagon, it was impossible to see through the enveloping cloud of steam; consequently I have since lowered the wagon body height by some 2" and am devising a clip on chimney deflector to hopefully cure this problem.


Perhaps it would be of interest to other owners for me list the additions and alterations that I have incorporated in "Nutmeg":


  1. 7lbs lead weight behind front buffer beam (made by melting lead into a standard Colmans mustard tin, removing the tin when set and bolting a brass plate on top).
  2. Dummy front sanders made from 3-in-1 oilcans with brass furniture knobs and copper pipe, with non-working brass rod lever to cab. Lead filled.
  3. Brass lamp brackets (front on chimney base, rear on cab upright).
  4. Saddle tank drain made from lorry valve stem and cap (would have been better in balance pipe).
  5. Plates on piston and valve gland nuts locked.
  6. Extension tubes (brass) on safety valves with 1/16th drain holes just clear of valve tops.
  7. Hang cross head pump valve from feed position to become by-pass valve and return to saddle tank.

An incidental benefit of the by-pass is that it now serves as an efficient hydraulic brake when closed. The Ness Islands line terminates at the bottom of a 1 in 50 blind curve at which the "pay train" loads it's customers, so it is essential to approach with caution. My usual procedure is to descend the bank with the regulator shut, blower on and by-pass closed, with a final slip into mid gear to draw up behind the other train.


  1. Roof hatch made so that controls and gauges can be seen - this also helps to deflect the exhaust steam.
  2. Fitting non-opening side bunker doors and fitting dummy coal loads to bunker top.
  3. Fitting collars to weigh-shaft to stop side-to-side oscillation.
  4. Fitting black and white barred plate behind gauge glass.
  5. Fitting bleed valve to top of gauge glass to prevent air locking when filling.
  6. Fitting "O" ring to regulator shaft to create friction to ensure "feel" is not dependent on gland packing.
  7. Changing fire door catch to gravity type.
  8. Replacing round cab stays to flat type and secured to rear side, not top of saddle tank.
  9. Fitting brass screws with lock nuts to cross head pump bracket.
  10. Fitting longer 5mm bolts to longitudinal springs at front stretcher, complete with self-locking nuts.
  11. Fitting extra grub screw to smoke-box door.
  12. Drilling lubrication holes in cross head above con-rod small ends.
  13. Fitting longer brake hanger bolts to be able to adjust position of brake blocks.
  14. Modifying ash-pan fixing by threading chassis and screwing tapered bolts into free holes in ash-pan. This assists in dropping pan onto pony truck arm complete with grate, so making it easier to drop fire and remove the grate.
  15. Drilling drain holes in ash pan as waters can enter when blowing down.
  16. Altering saddle tank filler cap so it has collar and no longer screws onto internal rod.
  17. Making larger control wheels for most of valve fittings so as to be better scale effect.
  18. Fitting injector (standard) drawing cold water from large tank in tender.



I trust these ideas (some from friends) will be of interest. I have two queries however - answers to Mick Morgan please:

         Is it worth while lagging the boiler and

         Is it worth lagging the steam pipe



By B M Watt, Kessock Light Railway


One answer to the above came from Russell Gant of the Willow Wood Railway:

As a Pearl owner, the modifications that you suggest all seem a good idea. Our Loco. (works number 022 - quite an early model) runs excellently and does have a lagged steam pipe. Obviously we have never run the loco. with the lagging removed, but I would say it must have made an improvement to the steaming or the original owner would have taken it off !
Our boiler is not lagged, so if you try this and the results are good, drop a line to Russell Gant.


Post Script :

  Just having looked at the website and read with interest the article on pearl mods, NUTMEG, I wondered if you might be interested in an extra little footnote to the page from the current owner of the engine in question on how it still performs now in the 21st century as quite an old Maxitrak pearl??

  I dont get to run the engine as often as I would like, but I do own NUTMEG and though she is getting a bit long in the tooth now, she still works OK with a few minor touches every now and again, on my home track at the BRADFORD MODEL ENGINEERS CLUB , NORTHCLIFF WOODS IN BRADFORD, WEST YORKS.

Yours, Sean and Nutmeg.