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Rose Canyon Union Station Centre City SD&AE Freight Yard AT&SF Freight Yard National City Yard San Ysidro and Tijuana Valle Redondo Tecate Campo and Clover Flat Hipass Jacumba Carriso Gorge Dos Cabezas Plaster City Seeley El Centro Cutoff Engine Facility Imperial Ave Encanto Lemon Grove La Mesa Grossmont Summit El Cajon Foster Trolley Underpass Silvergate Power Plant to National City Meat Packing South Bay Branch San Ysidro Loop Dispatcher Room Plaster City Narrow Gauge Aljibe Burnt Ranch Lime Vance Nada Grande Cima

HO Layout at a Glance


The San Diego Model Railroad Association HO layout is based on the prototype San Diego and Arizona Eastern Railway line from San Diego Union Station eastward through spectacular Carriso Gorge to the desert floor at El Centro. Connections to the Santa Fe at Union Station provide traffic outlets to the North toward Los Angeles, and at El Centro connection with the Southern Pacific Railroad continues Eastward. Total distance on the prototype is approximately 150 route miles. See San Diego area map

The HO layout models selected points along this route, as shown on the layout diagram page. Scratch built historic structures are included as needed to provide recognizable locations around the layout, as well as fulfilling the obligations of a member in the San Diego Model Railroad Museum. Other scratch built structures, while not exact replicas of existing (or historical) buildings, capture the flavor of a region and fill in the scene.

Three route maps are available for the HO layout. These are:

  • The MAINLINE from Rose Canyon and the hidden North Loop to El Centro and the East Loop balloon track.
  • The BRANCH LINE from Centre City East to El Cajon and Foster and South to the Mexican border at San Ysidro. Trolley wire covers much of the branch trackage.
  • The HON3 NARROW GAUGE from Plaster City up to the summit at Cima and Nada Grande.
  • For those who prefer the actual track configuration, this huge LAYOUT TRACK PLAN or the ONE PAGE DRAWING conveys the scope of the San Diego Model Railroad Association. If you have trouble with the javascript version of the LAYOUT TRACK PLAN display, try this alternate track plan drawing (no automated links).

    Note: LAYOUT TRACK PLAN file was pre-loaded on this page.
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    Station names (below) also link to the large layout track plan drawing.



    1. Rose Canyon -   As you enter the museum, the first view is the hills of Rose Canyon. The ATSF double track mainline winds along the creek bed and into San Diego. Pacific Highway parallels the mainline at this point, and on the west side is the site of the old Lindberg Airport terminal as it existed in the 1940’s. Just a small portion of the terminal area is modeled, with the runways and other airport service areas off the layout into the public aisle way.
    2. Union Station -  (detailed description)   This grand edifice, constructed by Santa Fe for the 1915 Panama-Pacific Exposition, is modeled full scale from original building blueprints. The SD&AE shares the terminal, and trackage rights South through downtown.
    3. Centre City -   Several blocks of the downtown area from Union Station to Market Street are under construction. Operating trolley starts at the loop on Broadway in front of Union Station and double tracks (in the street center) lead East to India Street, turning Southward, and continuing to the intersection at Market St. and Imperial Avenue. Double track trolley turns West and continues along Market St., crosses the mainline, and terminates at the Ferry Landing loop. Single track leaves the Centre City area along Imperial Ave. into the East Line branch. See below. Double track trolley also runs from Market St. along Kettner Blvd. Back to Broadway at Union Station.
    4. SD&AE Freight Yard -   Market St. the San Diego and Arizona Eastern leaves the ATSF tracks and enters a modest freight yard. Also at this point the East Line branch winds its way along Imperial Ave, past the trolley barn, and begins its climb to Encanto, Lemon Grove, La Mesa, Grossmont Summit, El Cajon & Santee, finally to the desolate Foster. SD&AE tracks continue South paralleling the AT&SF mainline. Separating the SD&AE Freight Yard and AT&SF Freight Yard is the Harbor Drive Bridge. This impressive structure is full of odd details made necessary as it crosses the main line and trolley tracks at a 45 degree angle.
    5. AT&SF Freight Yard -   From the junction at Market Street South, the extensive 24th Street ATSF freight yard is seen. Industrial trackage on the West side of the mainline services warehouses, a piggy-back facility, molassas tanks, a marine fuel farm, and a large tuna cannery.
    6. National City Yard -   The original South terminus of the Santa Fe was National City, and a modest yard was constructed at that point. At the time period being modeled, National City was used to ice refrigerator cars bringing produce from the Imperial Valley for the trip Northward to markets at Los Angeles and beyond. Structures in the National City/South Bay area include the National City Depot (the oldest existing Santa Fe depot in the United States), National City Meat Packing, Union Ice at the icing docks, a tank farm, bulk cement plant, steel fabrication plant, a lumber yard, and a sand and gravel facility.
    7. San Ysidro and Tijuana -   The SD&AE tracks merge just South of National City freight yard and continue to the international border. The trolley line stays on the U.S. side of the fence line, but the freight mainline crosses into Mexico at this point. Replicas of the San Ysidro freight house/depot and the Tijuana Depot have been faithfully modeled. As the railroad passes through Tijuana Eastward, a number of unique Mexican structures can be viewed.
    8. Valle Redondo -   Single track mainline climbs Eastward from Tijuana through rugged mountainous terrain. Reaching the great loop at Valle Redondo with mountains on one side, a broad valley on the other, there isn’t much to see. There is a beautiful Spanish Architecture station and some cattle pens, but not much else. The railroad soon passes into more tunnels and cuts through the mountains.
    9. Tecate -   The dominating feature here is the huge Tecate brewery. The small passenger station across the street is a busy place because all Mexican passengers must be off the train before it re-crosses the border into the United States. The border is actually inside International Tunnel.
    10. Campo and Clover Flat -   The town of Campo, just on the Northern side of the border, sports it’s own station. Camp Lockett has transitioned from horse cavalry to more modern modes of transportation, but men, food, and equipment are still hauled by rail. Eastward the grade becomes steeper, and elevation is gained in a horseshoe loop at Clover Flat. A feed mill and engine service facility for helpers can be found here. The large steel Campo Creek Viaduct crosses Hwy 94 and the line continues its climb to the summit at Hipass.
    11. Hipass -   Hipass contains a wye for helpers, and a passing siding. There are no structures here.
    12. Jacumba -   Another passing siding and a station track provides space for downhill trains to wait for uphill traffic coming through Carriso Gorge. A spur (Dubbers) just beyond Titus, and Eastward from Jacumba, allows bad order cars to be set out before continuing down the steep grade to the valley floor. A fictitious branch leaves Jacumba and cuts back into the mountain to a small mine at Cima. This is the upper end of the 3ft narrow gauge and a modest amount of dual gauge track is under construction.
    13. Carriso Gorge -   The awesome Goat Canyon trestle, second largest timber trestle in North America, dominates the gorge area. This is only one of many timber trestles in Carriso gorge, with much of the remainder of the track passing through tunnels. Clinging to the side of the boulder strewn mountains is Carriso siding. While the prototype railroad shunned signaling, Carriso siding was protected by semaphores at each end. The terrain is dry and desolate, vegetation sparce, and other than the occasional flash flood, no water. A few desert palms struggle to survive in the canyon floor in Carriso Gorge.
    14. Dos Cabezas -   A passing siding, a helper siding, and a bad order spur mark this point of the railroad as it descends out of the mountains. A water tank for thirsty steam engines is the only structure.
    15. Plaster City -   Plaster City is the lower end of the 3ft narrow gauge. This was the big money maker for the SD&AE as gypsum was brought in by narrow gauge hoppers from the mine, crushed at Plaster City, and loaded into cement hoppers on the SD&AE standard gauge. Also at Plaster City is an extensive complex for making wallboard, also shipped out on the SD&AE. Plaster City sports a small depot, transporting workers and equipment parts to and from El Centro.
    16. Seeley -   A passing siding here doubles in slack times as storage for hopper cars working the sugar beet loader. A spur for empties and a loader siding complete the area. Other than the beet loader and a rural gas station on the network of dirt roads, Seeley offers little. The farming community of Seeley is not modeled because of space limitations.
    17. El Centro -   El Centro in the 1940’s wasn’t much of a city, but it looked like a million bucks after traveling through the mountains on the rail line. Here one finds another ice house and icing platform, and a portion of the downtown buildings. Two impressive passenger stations sit side by side. The SD&AE and Southern Pacific, although married on paper, somehow felt the need to each have passenger facilities of their own. A couple team tracks across from the stations handle light freight while spurs behind the station area house engine service facilities (water, oil, etc). The Southern Pacific line continues East off the layout, and a balloon track through the industrial and farming areas turns SD&AE trains for the trip back to San Diego.
    18. Cutoff -   End to end from the Rose Canyon loop to the El Centro loop is about 15 scale miles on this HO layout. A cutoff track through the wall connects these two ends of the railroad. The cutoff may be used to operate as a “Christmas tree” operation when short handed, or to quickly route a train to the other side as needed at the end of a day’s operation. The cutoff simulates two actual portions of track on the prototype. The West end represents the AT&SF branch out to Miramar, while the East end represents the Holton Inter-Urban Railway between Holtville and El Centro. To be fair, neither end is more than a foot or two of track, but at least it justifies the occasional traffic suddenly disappearing.

    An engine service facility is planned for both steam and diesel as the layout generally covers the period of the late 1940s and early 1950s. A final design has not yet been completed.

    1. Engine Facility -   For steam an eight stall roundhouse and turntable (perhaps some garden tracks also), coaling tower, water column, ash pits, etc. For diesel, a four track engine house and transfer table, fuel oil, wash stand, etc.

    The East branch line was originally constructed as the San Diego, Cuyamaca & Eastern. It was originally planned to be narrow gauge, but was built instead as standard gauge. In 1889 tracks reached as far as Foster, just over 25 route miles from San Diego. The San Diego & Arizona Eastern absorbed the SDC&E, and eventually track East of El Cajon was abandoned. Today, trolleys again reach Santee.

    1. Imperial Ave -   The branch line begins it’s Eastward climb here. As you pass the Porter Pickle Packing Plant, the natural gas storage tank, and the trolley barn, the line crosses a duck under and begins hugging the divider wall. Other historic structures are planned along Imperial Avenue.
    2. Encanto -   There are no trackside structures in this area. The line passes through a cut here.
    3. Lemon Grove -   The quarry at Lemon Grove is actually located between Lemon Grove and La Mesa, but because of layout geometry it was placed between Lemon Grove and Encanto. Lemon Grove was an important citrus and produce supplier, and a siding and spur track was located just beyond the unique passenger station. The station is not yet modeled but is planned.
    4. La Mesa -   Site of Satterlee Butane, John Wood Rock, and numerous light industries. The La Mesa Depot today is part of the San Diego Railway Museum, preserved as it existed when commuters to San Diego took the train.
    5. Grossmont Summit -   This cut through the hills brings the branch line into El Cajon.
    6. El Cajon & Santee -   Again, light industry dominates this area. A housing tract is under construction on the hills overlooking the El Cajon valley.
    7. Foster -   End of the branch line. A trolley loop (12in radius) is hidden out of sight for continuous trolley operation. Sensors on the contact wire automatically control the loop turnout as needed. For 2-rail steam and diesel operations, a wye is provided. There is also a run-around siding (electrified) available for any locomotives unable to use the wye and/or unable to handle the sharp radius loop. An abandoned trolley helix drops down from Foster to the Cutoff track. Wire was removed inside the Cutoff because of clearance problems with double stack cars.

    No discussion of the branch line would be complete without mention of connections to South Bay. The SD&AE tracks paralleling the AT&SF tracks toward the border pass the AT&SF freight yard next to the operator aisle. The trolley connection heads South from Market street along the glass on the public viewing aisle. A small passing siding at Barrio Logan permits trolleys and other traction freight to pass. From there, the track & wire continue through an underpass (with a killer 7 ½% grade!) and rejoins the branch at the Silvergate Power Plant.

    1. Trolley Underpass -   Above the underpass will be a large tuna cannery complex. On the other side, the maze of pipes at the agar processing facility will obscure much of the trolley’s re-entry to level track.
    2. Silvergate Power Plant to National City Meat Packing -   The Santa Fe freight house sits across the street from the power plant but is actually served from SD&AE tracks, not AT&SF. Numerous small spurs continue into the South Bay serving a variety of warehouses and small industry. Tomorrow's steaks can be seen in the stockyard adjacent to National City Meat Packing.
    3. South Bay Branch -   The branch passes a steel fabrication plant, a small street scene, and the Sunkist citrus packing house curving along a spur at the last branch line siding. The SD&AE merges with the AT&SF at National City, while trolley wire extends past the gravel works to the border at San Ysidro.
    4. San Ysidro Loop -   At the international border fence line the trolley line enters a tunnel and loops out of sight inside a mountain. Again, automatic turnout control is provided with sensors on the contact wire. For those individuals operating 2-rail equipment through the loop, a track occupancy indicator is installed in the loop itself to facilitate manual throttle polarity reversal.

    The future CTC equipment and dispatcher will be located under the mountain at Jacumba. At this time this area is used for construction of large structures, and to house computer equipment for generation of switch lists, etc.

    1. Dispatcher -   Although contained entirely inside the mountain, the dispatcher will be able to view any of a dozen cameras around the layout, and will control turnouts over the entire 15 scale miles of mainline. Communication to individual train crews is via headset radio.

    At Plaster City, the SD&AE interchanges with a 3ft narrow gauge railroad. The Pacific Portland Cement Industrial Railway hauls gypsum from a mine near the San Diego / Imperial Valley county line into Plaster City (now the name is obvious), producing bulk plaster and wall board, etc. Featureless terrain lies between the mine and Plaster City.

    1. Plaster City Narrow Gauge -   A strange assortment of structures is the processing end of the narrow gauge. A very short section of dual gauge exists on a spur.
    2. Aljibe -   Steam engines can take on water here before crossing the Fish Creek Trestle.
    3. Burnt Ranch -   This fictitious location represents a typical high desert town. The superb detail throughout the area cannot be seen from the public viewing aisle.
    4. Lime -   A passing siding and whistle stop passenger platform helps operations. There is increasing interest in HON3 within the association, often needing all four throttles.
    5. Vance -   Another fictitious site patterned after a Nevada mining town. A small mine, complete with 2½ft gauge track, seems abandoned through the weeds. An “armstrong” turntable and 1 stall engine house allow helpers to be turned and serviced.
    6. Nada Grande -   A collection of dual gauge sidings and spurs allow use of this wholly imaginary mining complex by standard gauge. A recent collapse in the mine may have slowed revenue traffic, but a variety of standard and narrow gauge trains brings in needed supplies for the repair effort.
    7. Cima -   End of the line of the fictitious narrow gauge line. Dual gauge track permits standard gauge access to the Nada Grande mining complex by standard gauge trains. The Cima standard gauge branch connects with the SD&AE at Jacumba Hot Springs. Much of Cima is narrow gauge only, including the passenger station and engine service facility. The narrow gauge connects with the town of Vance via the rugged 2.2% Esconda grade.

    This concludes the tour around the San Diego Model Railroad Association's HO layout.
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    Standards Standards and construction details from 1980 to the present.
    Video Video Clips of the HO layout (.mpg format)
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    References References (Articles, Books, Videos)

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