Their effort, which involves climbing Ben Nevis, Scafell Pike and Snowdon, also has to include the travelling time - but they have a major inspiration to speed them on their way.
In June the Forth Valley officers issued a donation request - which in itself is very rare - after learning that colleague Cameron (Cammy) Shanks had been diagnosed with terminal stomach cancer, with a six to ten months’ life expectancy.
As an officer who has given 40 years’ service to the public he is held in particularly high regard by fellow officers.
Cammy’s own response to his diagnosis has been to urge support for Maggie’s Centres in Forth Valley, who are supporting him and his family, and very many others besides.
A spokesman for the Three Peaks Challenge volunteers said: “Although this will be a tough challenge physically and mentally for our officers, it is nothing compared to the challenge that Cammy and his family, and others with cancer diagnosis, face.
“Although we have managed to achieve our initial target, any donation for this fantastic charity is very much appreciated by both Maggie’s and Cammy, and any additional shares that you can give this post to increase the awareness is very much appreciated by our Division”.
Cammy is married to to Claire and has four grown up children, and a recently-born a new grandchild.
He said: ”I have turned to Maggie’s for the help and support that I need, and I have to say, words do not describe how much their support helps to both me and my family”.
To contribute, visit http://www.justgiving.com/fundraising/fvpolice-maggiesfv