Parks,
What I was saying about variables is that for Titanic in the bow port holes are in compartments # 2, 3, and 4 which is the three foreward cargo holds. If those portholes were left open on the Lower
G-Deck they would allow more water to enter those three compartments and given the forepeak compartment would have been damaged itself along with Boiler room #6 and the coal bunker leaking in Boiler room #5, all that weight even with the bulkheads raised up would have allowed the portholes on F Deck above Boiler room #6 and 5. If those portholes were opened water would have been able to add to the rate of flooding in Boiler room #6 which was damaged badly to begin with, and Boiler room #5 which Fred Barrett said water was coming in as if through a firehose, which the pumps could handle and keep that compartment dry but with the port holes open on F deck above that compartment water would have been able to flood the lower decks and increase the rate of flood in that compartment. Eventually if enough port holes are open it would eventually bring D deck under. Im fairly sure port holes above Boiler room # 4, 3, 2, or 1 had the possibility of being open, most likely they wouldnt considering G deck had the post office, the mail baggage rooms and the third class open berths.
Titanic sank till water on the outside of her hull was at D deck just below the anchors. In this situation the D Deck gangway doors would be a good 3 to 4 feet (estimate) above the water line on the outside of the hull. In this situation with Titanic having say Bulkhead 4 and 5 (bulkheads infront of and behind Boiler room # 6) raised two decks higher in this situation if any of the port holes were left open on E deck by any of the passengers these port holes would have allowed water to flow into Titanic anywheres from the No. 1, 2, 3, 4, 5, 6, 7, or 8 compartments. These compartments would have all E deck port holes fully under or at least half way under the water line. This means that if passengers left their port holes open in this what if situation with titanic having some if not all bulkheads 2 decks higher, port holes left open would play a major role, would allow water to enter compartments that werent flooded and if for instance Boiler room #5 flooded faster than the pumps could handle and the weight would have been enough to pull the D Deck gangway doors low enough that water could start flowing into Titanic on D Deck. (if the bulkheads were raised two decks higher at bulkhead # 6 that would have put the water tight bulkhead on D deck just behind the aft most D Deck gangway door. Wouldnt have been possible to do this considering the grand staircase and elevators would have been in the way and the design would have to really be changed. Back to the situation in this what if, water pouring in through the D deck gangway door left open after Lightoller had it opened to load more passengers, water would have been able to flow freely down D deck to the bow till it encountered Bulkhead # 5 which would stop water transmitting foreward on D deck. This means that water would pour down into Boiler room # 5 increasing the rate of flooding further more making the pumps useless in keeping the compartment dry. By time the D deck gangway doors were fully underwater, water would be pouring over the sides onto the well deck area and the folksel is just inches above the ocean at this time. Once water gets on the well deck you can kiss goodbye the thought of keeping her afloat. Can possibly keep her afloat long enough to get all off, but she would eventually sink with her upper most deck under water in the bow.
The basics of what I am saying is that even in a what if situation that the Titanic had some bulkheads 2 decks higher to allow more compartments to flood without sinking the ship, it is still possible for Titanic to sink if water was allowed to enter the ship in different locations. Port holes left open by passengers would have allowed water to flood the same compartments or allow water to flood compartments not damaged, the D deck gangway door left open if it got enough water in her to bring that door under water, that would have increased the rate of flooding considering that door would have allowed almost if not the same amount of water into the hull into other compartments that the damage from the iceberg was allowing to freely flow into the first 6 compartments.
