Primarily in the 1970s and 1980s Tomy released a few different cargo loading and unloading gimmick sets for the Plarail system, commonly with logs and Round-Trip Plarail components. In the 2000s several of these cargo gimmicks were revisited, often in conjunction with the Thomas the Tank Engine series and its exports.
In 1973 a log loading station and unloading platform and pen was developed for the DD51 Diesel Train Set, which included both stations and the titular DD51 hauling two yellow and green log wagons around an oval, picking up and dropping logs off. This set has the earliest versions of the accessories - namely, the drop off station has round holes in the tooling for the old style of tall roof supports and the loading station has the dropping mechanism contained in the upper white section with a hollow section of the track base. This set can be seen at the bottom of this page in the Plarail Museum.
Also in 1973, the loading and unloading stations were released as individual accessories. The single Loading Freight Station (積みこみかもつ駅) is of the earlier type with hollow track base and can be seen on Vio's blog here. The individual Unloading Freight Station (積荷おろしかもつ駅) is also the earlier type with round roof supports and includes a tipping car and two logs as well as three fence sections (it can also be seen on Vio's blog).
In 1974 the C-12 Forest Railway Set included a new version of the unloading station using the new style of supports developed for the station platform, with later production examples changing the loading station to have the triggering lever in the track base, interconnecting with the upper section. Both styles of set can be seen in the Plarail Museum.
In 1975 the updated style of loading and unloading station were used in the export Playrail Chug-A-Log Choo Choo. The log loader has the solid base with lever and a localized sticker.
Actually, the unloading station is a slight tooling variation - although there is not even a roof provided, the slots for inserting the supports for one now face the same way, as opposed to being mirror images as on the 1974 Plarail C-12 set version. According to the box, the fence pieces for these sets were manufactured in the United States. They are made of hard plastic and are somewhat fragile.
The set includes a green and yellow log tipper wagon and two logs.
Around 1977 the loading and unloading station were produced in Hong Kong for the Palitoy Discovery Time Log Delivery Train Set. The loader is the updated style, again with an exclusive sticker.
The log unloading pen is similar to (and has eyelets facing each other like) the C-12 Forest Railway Set but it is made in Hong Kong. As it has the roof, a localized hanging Timber Yard sign is also included. The fence is also made of a somewhat odd soft plastic, although this helps it slot together nicer than the American fences, which are often cracked.
Two green and yellow log wagons and six logs, all made in Hong Kong, are included in the Palitoy set.
A very cool accessory... it was also used in the Geyper Play-Rail series, although I think it was produced in Spain like most of the other Geyper components.
In 1977 these components were used again in Japan in the Round-Trip Plarail ED-70 Pull-Down Set in green instead of blue with a round-trip ED-70 locomotive hauling a log wagon and a ball-carrying car. The unloading station tooling was modified to be able to tip both cars.
In 1975 for the new Round-Trip Plarail system a loading hopper (つみおろしホッパー) that loaded balls into a tipper car that could also dump them back into the upper hopper. This was used in the shuttle train-type Round-Trip Plarail Three-Dimensional Loading Set with the reversing engine going up and down a slope picking up and dropping off the balls. In 1977 the loading hopper was also included in the ED-70 Pull Down Set, although there was not an elevated rail to automatically dump the balls back in the hopper. Both sets can be seen in the Plarail Museum.
An awesome 1980 gimmick set included the only release of an EF-15 with light feature as well as the exclusive cargo container loading station that has a forklift alternately loading and unloading a special container onto an open flatcar. A truck that can also hold the container is also included.
The first Round-Trip Plarail set of the 1980s evolved the original log loading and unloading stations into a single stacked unit, with a larger base section with loading trigger arm that supports an upper dumping section that causes the train to tip the logs back into the loader, letting it cycle automatically.
The structures loading and unloading sections are based on the same mechanism as the 1970s log pens.
A very cool gimmick.
This log loader was produced again in 1986 for the last Round-Trip Plarail set in a color variation. These are probably the coolest of the older log loading and unloading stations, as they allow for completely automatic cycling operation.
In 2000 Tomy released a large storage box that folded out to become a two-level city scene with airport, parking lot, and a freight loading section with black balls for the included yellow tipper wagon. If set up right, a train can cycle the balls around between the two levels. This box for this set can be seen in the Plarail Museum.
The 2002 Thomas-series Thomas and Terence Loading and Unloading Set included two large loading and unloading base sections that incorporate a Motor Tomica Terence the Tractor who can carry logs around, picking them up from one station and taking them to another where they can be loaded into the special tipping log car.
The base sections include gates and levers to properly sequence the train and tractor, with Motor Tomica turntables and wheel pickups to make Harold's rotors spin and the trackside crane move. Both the train and Terence travel up and down to be able to unload and load properly.
In 2006 a new ball-loading "quarry" accessory was developed and sold in sets and individually in all of the major Thomas Plarail and export regions. The accessory features a conveyor turned either by crank or the stopped train's wheels that lifts the balls up to a switchback chute that deposits the balls back into the tipper car. More information can be seen on the Sodor Quarry Loader page.