The Third Avenue Bridge is the single largest structure on the CNJ Bronx Terminal layout. To present it adequately, I’d have to break it down into the individual pieces – access ramp, abutment, girder bridge with rest pier and swing bridge.
The bridge abutment on the Bronx side of the Harlem River is the only part of the Third Avenue Bridge that closely integrates with the Bronx Terminal. An access track under the Third Avenue Bridge connects the “New Yard” added in 1929 to the Bronx Terminal. The track leads through an arch (which looks like a tunnel) that was part of the original design of the bridge. It was a natural choice to begin construction of the bridge with this key element. There is little information on its size but the known dimensions of the new bridge together with the existing plans and photographs of the original bridge help understand its design and allow to estimate approximate dimensions.
Third Avenue Bridge Abutment on Bronx Side
On its own, the abutment is a massive, fortress-like cubic structure built of granite blocks, roughly 100′ long, 100′ wide at its widest point on top of the arch and 70′ at its narrowest point where it connects to the access ramp. Its height above ground on the Bronx side is an estimated 22′. Two stairs lead from the deck of the bridge to the ground level on both sides. The one on the south side ends close to the turnout which joins the two curved tracks from the transfer bridge. The new bridge from 2004 still has stairs at almost the same position. Taking the current number of steps (21+21+2) and assuming similar dimensions of the steps (7″ rise and 11″ run) results in a slightly higher bridge deck, however, so it will have to be fewer steps.
The arch’s portal is flanked by four turret-like reinforcements of the wall. The same reinforcements are used along the entire bridge wherever a massive pier braces pieces of the bridge and the ramp. The reinforcements are covered by two carefully sculpted blocks of stone that look like the roof of a pagoda. On top of each second block sits a street light pole.
Scratch-building the Abutment
One of the first adjustments I had to make to the original design was to accommodate for the turnout and the diverging track that leads over the triple diamond to the inner track of the transfer bridge. To simplify the construction of the triple diamond, I changed the angle of the diverging track so that the switch moved further into the tunnel (whereas in reality the switch was completely outside of the bridge). This meant that I had to slightly increase the opening of the portal to make it wide enough for the 40′ box cars coming from the diverging track. I also simplified the construction of the railings along the top and the stairs. In both cases I extended the block wall so that it functions as a parapet.
I first built the structure of the abutment with .040″ Styrene (and with .080″ where it had to be stiffer). For the walls I used the Faller Archway of Natural Stone Ashlar (painted styrofoam, #272600 and #272650) which I glued on thin basswood. I chose the product because the arches have the correct size and look for the bridge’s portal. The wall captures the fortress-like character of the abutment very well even though it slightly overdoes it. For the stairs I used .040″ Styrene strips. The street details had to wait until I’d have the adjacent pieces ready. I finished the abutment walls and stairs by air- and dry-brushing them to give the walls some depth.
Girder Bridge
As mentioned before, the swing bridge is sandwiched by decks on steel girders on both sides of the Harlem River. The girder bridge between the swing bridge’s rest pier and the abutment on the Bronx side is about 90′ long.
To scratch-build the girder bridge, I used Styrene strips or sheets, mostly of .040″ thickness. The 5.5″ wide deck rests on four girders. The web of the outer girders is made of 1/2″ wide Styrene. On the web I glued flange angles, stiffeners and flange plates based on thin Styrene strips or angles. The deck has four lanes enclosed by relatively wide sidewalks on both sides. This provides enough space for the bridge house on the south side.
For the sidewalks I used MonsterModelWorks’ Cracked Joined Concrete product. To paint and weather I ink-washed and dry-brushed the wood. The outer two lanes are made of about 1″ wide .080″ thick Styrene and air-brushed in gray. In the two cobblestone covered center lanes, I inserted N scale street tracks for the Third Avenue Railway System (TARS) trolley. By the mid-1950s those tracks had disappeared, but I decided to include them on the bridge to add some color. The tracks are electrified and fully functional. A TARS Brill N scale trolley from Bachmann with DCC services the short section on the bridge.
Swing Bridge Eastern Rest Pier
For the rest pier, I had to rely entirely on photographs. The massif pier covered with granite stone has a similar appearance as the abutment and the piers under the bridge’s approach. The rest pier is flanked again by turrets that reach about 7′ above the deck.
Almost all of the pier is made of wood – the core is basswood while the walls are made of MonsterModelWorks block stone sheets. For now, the rest pier marks the end of the Third Avenue Bridge on my layout.
