When the Layout Gets Big Enough to Lose Track
Somewhere around the 200-car mark, the mental index breaks down. You know you own a Walthers Trainline gondola painted for BNSF because you bought it in 2019, but you cannot tell whether it's in the blue Plano tray on the third shelf or still in the original manufacturer box in the staging drawer. You've got two Athearn blue box GP38-2 units, and one has the factory Atlas decoder at address 3 and the other still runs on DC because you ran out of Digitrax DH165s during the last layout session. Neither of those facts is written down anywhere. They live in working memory, which means they live nowhere useful.
The fleet doesn't have to be enormous before this stops being manageable by feel. Fifty cars across three scales — HO, N, and the odd O gauge piece inherited from a deceased uncle — with different storage locations, mixed decoder states, and a handful of kits in various stages of completion will outpace a hobbyist's memory faster than most people expect. The problem compounds because model railroading is an acquisitive hobby. The railroad never stops growing.
The Fields That Distinguish a Record Worth Having
The Item Type field makes the first architectural cut: Motive Power, Rolling Stock, Structure, Accessory, Electronic Device, Other. This matters because the data model for a steam locomotive and a double-stack intermodal flat are not the same, and cramming them into identical records forces compromises everywhere.
For rolling stock, the Car Type taxonomy — Box Car, Flat Car, Hopper (open), Hopper (closed), Gondola, Tanker, Caboose, Log (center beam), Log (trucks only), Auto Racks, Intermodal, Hopper (ore), Cattle, Specialty, Passenger — provides the first filter dimension. A collector who runs a 1960s transition-era layout can isolate all Passenger cars with a single filter. A freelancer building a coal-hauling shortline can pull every Hopper variant in the fleet and assess what's actually run-ready.
The Power Type field handles motive power classification: Steam Locomotive, Diesel/Electric Locomotive, Unpowered Unit, Electric, Other. Combined with Decoder Address as a separate integer field, this creates an auditable DCC address registry. When you've assigned address 72 to the BLI Challenger and address 72 to a Kato P42 Genesis you forgot you owned, and both engines end up on the main at the same time during an ops session, the resulting behavior is embarrassing. The address registry prevents that.
Ideal Weight versus Actual Weight with the 1oz + 0.5oz-per-inch formula calculates NMRA RP-20.1 target weight against what the car actually weighs. The gap tells you which cars need lead weights before they'll stay on the rail at speed through curves, particularly in N scale where the tolerances are unforgiving and a light car is the first one off the track at the approach to a 9.75-inch radius.
The Keywords multi-select field carries the operational punch: Needs Painting, Needs Decals, Fleet Ready, Oddity, Foreign Prototype, Needs Weathering, Needs a Load, Sell, Tinplate, Craftsman Kit. Filter on "Fleet Ready" and you see exactly what can go on the layout tonight without prep work. Filter on "Needs Weathering" and you have the queue for the next painting session. Filter on "Sell" and the consignment list for the next club swap meet is already sorted.
Finding the Right Car When the Clock Is Running
Saturday ops session, guests arriving in forty minutes, and the local turn needs four 40-foot box cars spotted at the team track interchange. The ones that were supposed to be Fleet Ready are in two different storage systems — one Plano tray labeled "ready," one shelf with boxes that haven't been touched since the last move.
Pull up the inventory, filter Car Type = Box Car, Keywords includes "Fleet Ready", Condition = Excellent or Good. Twelve cars come back. The Container ID field, linked to a separate storage locations library, shows exactly which physical tray or box each car lives in. Three of the twelve are in Tray 7, two are in the labeled shelf bin, the rest are scattered across four containers.
That filter-and-retrieve sequence takes thirty seconds in the database. It takes eight to twelve minutes of physical searching without it, and you find out a car you flagged as Fleet Ready still has a broken coupler knuckle the first time you try to make a pick at the interchange.
The Barcode field, populated during initial data entry by scanning the manufacturer's box barcode, provides the lookup anchor. The Model Maker, Model Series, and Model Number fields together with Road Number and Railroad prototype give enough specificity that when you're standing at a swap meet evaluating a used Athearn Genesis AC4400CW at $85, you can verify in under ten seconds whether you already own one and what condition it's in.
The Warranty date field on locomotive purchases matters more than most modelers track. A Soundtraxx Tsunami2-equipped brass import at $600 with a two-year warranty has a different financial profile than the same money spent on something with no warranty documentation. The record captures the purchase date, purchased-from vendor, and warranty expiration as discrete fields — not buried in a Notes cell.