Yes. And to stay closer to the English “I worked designing bridges” Fred could say “mi laboris desegnante pontojn.” No “-int-”, as he designed at the same time as he worked; "-e" instead of "-a" as it modifies the verb “laboris.”
Two items ago we were read sentence about a "pato de fero" and now we see a "ponto el fero." The inconsistency is annoying. There's also that sentence "ringo estas cirklo de oro," which it seems cleaar should be "cirklo el oro."