I'm not exactly sure if a transport wheelchair is different than just a regular wheelchair, but there is a place in 7th district that has medical equipment you can borrow. Sorry, I can't remember the name of the place. Let me google.
ACT
Anyone in need of medical equipment can call and leave a message on the ACTS answering machine at 301-769-4199. Members screen the machine daily to check on requests and persons wishing to donate items.