how to top rope off single bolt?

I know their was a spammer asking this a while back cause I found that thread but I was wondering legitimately how to set up an anchor off one bolt. I know its a bad Idea but the place I want to climb only has single bolts at the top and the route I want to do does not have any nearby cracks to put cams in as backup. The place I'm going is marymoor park in redmond Wa. in the mountain project description it says "All anchors are single bolts with one triangular shaped quick links." and when I went there today it appears this is still the case. also I know I like just created my account I do sincerely promise I am not a spammer I would just like to know if maybe there is a way to back it up on one of the bolts bellow it or something cause I am really interested. if this seems like a bad idea I will probably not set one up and just stick to the lead climbing their. I feel like its a pretty heavily trafficked spot and someone has to have set up a top rope there.

the place I want to set up a top rope:

https://www.mountainproject.com/area/107094045/marymoor-park-outdoor-sport-crag

thanks,

Lucas

Use a quickdraw and tape the gates shut. Ignore whatever 12 piece anchors the rest of MP will suggest

While top-roping, keep the rope clipped into the first bolt down from the top bolt as well. That way, if the top bolt fails—not likely, but could happen, you won’t go all the way. Others have already mentioned this technique on the other thread.

I don’t know this crag, but why were routes put up with only one bolt as an anchor? If they are massive Euro-style rings that are drilled deep, I’d be ok with it, but it seems like incomplete route building if they are normal bolts.

Top roping off a single bolt is generally a bad idea. What I would do (and basically what the second comment on the previous thread says to do) is clip the top bolt, and one or two more on the way down. That way, if the top bolt/gear fails, something below it will catch you. Outdoors, it makes sense to look for natural features to back up bolts, since you can use cracks, horns, pockets, and trees as anchor points. In your case, you could probably sling the top of the West Spire as a backup if thats where you're climbing. It's hard to tell from the pictures how close together the anchor bolts are, but you could probably also combine bolts for anchors. Here's a poorly drawn explanation of what I mean:

Make sure to run the rope directly through the hanger so it's quick and easy to clean up and go when everyone's done.

Lived in Seattle 10 yrs, know of the Marymoor cement playground you speak of. TR off 1 bolt in this case is probably safe since it is manufactured wall of cement and rebar (if outdoors, definitely use more than one point!). Honestly, even the highest walls are just highball boulder problems, throw a crash pad down below the route and you have your backup.

You over-emphasize that you aren't a spammer.

Place a second bolt. Problem solved for you and future climbers. 

Yur Gonna Die!

Toproping....

LOL!