SUBSIM Radio Room Forums - View Single Post - Fastest means of organising preflood from surfaced condition?

Fidd · 07-18-23, 06:38 AM

Hi,

Not that it's a manoeuvre I care for much, but some skippers like to proceed on the surface in a preflooded condition (13m3 in forward ballast, 5m3 in aft ballast). I've been practicing various methods to strike the right balance between speed of attaining the pre-flood, and accuracy in terms of nailing the required values.

I've found that blowing the negative ballast to 2m3, then opening forward MBT, and moving to close the valve as it passes 10m3 seems fine, with a very slight blow required of the forward MBT if one over-shoots the 13m3. The aft MBT valve is opened and closed for 1 second to achieve 5m3. (with practice). The negative tank is then fully blown.

I try to do the preflood using the e-motor and then readopt the diesels to prevent accidental flooding of the diesels.

Has anyone found an easier/better or more rapid method? There's so many possible permutations possible. It's not a manoeuvre I like because it's awkward, (from surfaced) risks making noise, uses air etc. On the plus side you sink like a stone if a crash dive or PD is required.

07-18-23, 06:38 AM	#1
Fidd XO Join Date: Apr 2005 Location: Blighty! Posts: 431 Downloads: 10 Uploads: 0	Fastest means of organising preflood from surfaced condition? Hi, Not that it's a manoeuvre I care for much, but some skippers like to proceed on the surface in a preflooded condition (13m3 in forward ballast, 5m3 in aft ballast). I've been practicing various methods to strike the right balance between speed of attaining the pre-flood, and accuracy in terms of nailing the required values. I've found that blowing the negative ballast to 2m3, then opening forward MBT, and moving to close the valve as it passes 10m3 seems fine, with a very slight blow required of the forward MBT if one over-shoots the 13m3. The aft MBT valve is opened and closed for 1 second to achieve 5m3. (with practice). The negative tank is then fully blown. I try to do the preflood using the e-motor and then readopt the diesels to prevent accidental flooding of the diesels. Has anyone found an easier/better or more rapid method? There's so many possible permutations possible. It's not a manoeuvre I like because it's awkward, (from surfaced) risks making noise, uses air etc. On the plus side you sink like a stone if a crash dive or PD is required.