The original H21 cars had no top chord and the car sides started to bow out. The PRR immediately added a top chord that covered most of the length of the top of the car's sides. However, eventually all of them (by around 1930) were replaced with full-length, all-around bulb angles (angles that flare to a thicker, bulb-like, shape on one leg). I decided to model that with 5" angles (Evergreen Scale Models part #292). The prototype drawings show 4"x3-1/2" angles, but using a 4" angle (part #291) was too small for this model, so I went with the next size up. I have one of the end pieces shaped and glued in place in the photo below. It takes quite a bit of work to get the pieces to be the correct length and have a nice 45-degree angle. You can see the two long pieces already shaped (but not yet cut to length) laying in the car.
The next photo shows all four of the top chords installed. It sure gives the car a nice finished look at the top.
For the drop-style grab irons I used Tichy 18" Drop Grab Iron (part #3501). There are six of them on the side, and five on the end in the corner shown here. It sure speeds up the work when you can buy these pre-formed, but they were all a bit crooked. I may try making my own for the future models and see which I like better.
The next photo shows the other corner. The straight grab irons were hand-formed using 0.010" phosphor bronze wire (Tichy part #1101). The other end of the car has the same grab irons installed.
The more I worked on this model, the more it irritated me that the end sills didn't look like the real H21a. There is a small curve down near the end of the end sill. I decided to mimic this using some 0.010" sheet styrene. I started by forming the end pieces first. They are 12" long and 18" tall.
I then cut and glued the top cover on top of the end sill. This one only needs to be 11" wide, because of the vertical plate against which it is placed.
Next, I cut and shaped the face plate, which hides some of the ugliness of the end sill. I wrapped it around the center sill and the coupler spacing. I cut its vertical dimensions a bit too long, as you might be able to see in the photo; this was filed down before the next step.
I then cut some 3" strips to form the bottom plate of the end sill. A little filing will make them line up with the ends of the end sill.
There are a pair of grab irons directly under the top of the end sill, so I installed those next. I eye-balled how far away from the side edge they were to go.
Here's a photo of the B end of the car as it stands now.
I installed the brake wheel housing at an approximate location, based on prototype photos. The majority of the photos showed the brake wheel sticking out above the car, but I figured that that type of construction would probably leave the brake wheel very vulnerable if I plan on taking this car to train shows, so I opted for the side-mounted brake wheel. I am not clear on when the railroad switched from one to the other, or if it was dependent on which builder they used for the particular car. In the next photo is also shown the platform deck under the brake housing.
It was then just a simple matter of drilling out a hole in the brake housing and gluing the brake wheel to it. I also installed some thin strips of styrene to resemble the platform supports, which seemed to be attached to the underside of the sloped sheet of the car on the prototype.
Absolutely the worst job I could have done, trying to line up the brake shaft down to the end sill. All I can say is that I'll try to do a better job the next time. There is supposed to be a chain connecting from the brake housing to the brake shaft, but I just couldn't muster up the patience to do it. There is only about 2 links' worth of chain to attach here anyway.
I noticed on prototype photos some bent-metal half-rings under the car's frame near all four corners. I presume this is some sort of lifting ring (I'm just guessing). I used some 0.020" phosphor wire and bent them around the stem of a small screw driver to try to get a consistent curve (see the photo inset). I then drilled matching holes in the bottom of the side sills and superglued them in place. (Update: I have been told that these are "towing shackles" and are used to move cars using a cable if no engine is available).
Next up were the door handles on the hopper doors. These came from the B.T.S. H21a kit that I never finished to completion. I asked Bill of B.T.S. to see if his separately-available hopper door latches (part #02307) were the same, but he said they are different. The parts on the web site are made out of brass, whereas the ones that came with the kit are urethane castings. I guess I'll have to buy two sets for the next car I am going to build to see if they are correct.
I then noticed a U-shape metal frame with rivets embossed on it around the coupler opening. I tried to simulate that with some 1-inch thick styrene strips. It also hides some of the ugliness of the center sill.
The final exterior detail I added was a set of carmer cut levers. These are made by Standard Railway Castings Company. The kit provides four different pair of cut levers. The ones that matched the H21a prototype photos is the set second from the left.
I'm not sure I'm going to do the cut levers again (the kit is great, and looks to be very accurate). I tried to position them matching the prototype, but they look a bit funky on my model (Update: once the model was finished and painted, they become less noticeable, so I may use them again). I also added some way-too-small poling pockets to each end of the end sills (I'll have to improve those on future models).