I did some quick research on documentation. The accounts given by crew members from a military hearing do not show up in the history books until about thirty years ago. The summary report from that hearing are found in the O.R., as does the initial reports, but not the detailed questions and answers that have been published in recent history. The testimony that the historians have focused on seem to contridict the summary and those reports found in the O.R. The contridictions are ...
1. When the Hunley was fired upon by small arms [O.R. reports the Housatonics crew fired before the Hunley got near the ship...the individual testimony statements say after the Hunley backed away]
2. When explosion occured [the O.R. reports say immediately at the time of contact...some of the testimony says after the Hunley backed away]
3. The length of time for the attack [the O.R. says the explosion occured about 1.5 to 2 minutes after sighting the Hunley...some testimony says up to six minutes after sighting the Hunley]
The O.R. reports never say the Hunley paused at the Houstonic or backed away, the attack was straight in and the explosion immediate.
The reports of the damage to the Housatonic was massive. The ship was found upright. The hole in the hull was said in the 1870s was big enough for a carriage and two horses to pass through (thats about 8 to 10 feet in diameter), the oak beams and thick planking were pushed in with great force, the bulkheads within the ship aft the main mast were gone, the propeller shaft was shattered in-two, the lower part of the rudder and rudder post were pushed aft, the stern frame was detached and resting on the rudder housing, the coal was scattered in the lower decks in heaps. The crew reported that the quarter aft starboard side was completely wrecked- thats about 80 to 90 feet of ship.
I believe that the researchers are focusing on the amount of damage to the Housatonic, how fast it sank, and that it sank upright- meaning the water flooded it immediately and completely, making the torpedo a large one (R. O. Crowley, CSN Torpedo Division, wrote they found that 50 pounds of powder would not do much harm to a ship- they built 100 to 2000 pound torpedoes to destroy ships- and the Housatonic was completely wrecked). Contempory writings in the 1870s state that the torpedo was a contact type that weighed 150 pounds others say it was 65 pounds with a barb and pull system, and that the Hunley's fragile bouyancy and control depended on the counterweights to offset the weight of the torpedo and length of spar. The belief then was that the Hunley, never testing the spar torpedo attack, once free of the torpedo, nosed up and became stern heavy, making control almost impossible. There was mentioned that there was supposed to be a sliding ballast to compensate for the loss of the torpedo, but I have never heard of this feature.