Anybody heard of using clothespins under the hood of a car?

I hadn't until this past week when I was looking under the hood of my grandfathers 37 ford.

There were about 10 clothespins clamped onto the fuel line where it was over the engine block...

I had to ask the neighbor who is also an old car fanatic about it, and he told me that they are there to pull heat off of the fuel line in order to prevent vapor lock... 

Learn something enw everyday...

He also said that you can use insulated lines to prevent this, but my grandfather never had the time to change the lines before he passed...