I Suggest you to review the following:

In COLREG rule 35, should be "... ring the bell rapidly for five seconds", not "ten senconds" as you can see below (and in you website):

(g) A vessel at anchor shall at intervals of not more than 1 minute ring the bell rapidly for ten seconds. In a vessel 100 meters or more in length the bell shall be sounded in the forepart of the vessel and immediately after the ringing of the bell the gong shall be sounded rapidly for about 5 seconds in the after part of the vessel. A vessel at anchor may in addition sound three blasts in succession, namely one short, one long and one short blast, to give warning of her position and of the possibility of collision to an approaching vessel.

I´m not sure what you´re getting at - the web site already says 5 seconds?

where are you seeing the 10 seconds?