Admiral William S. Benson, Chief of Naval Operations, to Vice Admiral William S. Sims, Commander, United States Naval Forces Operating in European Waters
CABLEGRAM RECEIVED June <18,1918> 20019. SFM.
Origin Opnav Washington. Ser.No. 7454.
Ref’d To O-1 Date June 21
S EC R E T
7454. An analysis of report of sinking of U.S.S.PRESIDENT LINCOLN brings out certain facts. Escort left about 13 hours before ship was torpedoed. At the instant of attack 4 ships of the convoy were steaming in line 800 yards distance or a total of 2400 yards from the left flank ship to the right flank ship. It is known fact that ships steaming in this formation present from certain points of attach and for each torpedo fired an unknown target equivalent to combined length of the total number of ships in formation,while column formation for each torpedo fired,can only jeopardize 2 ships nearest the line of approach of any torpedo for any chance fire. Under the circumstances outline above,a submarine carrying a 4,000 yard torpedo and fire at a distance of 1600 yards range on either flank from nearest ship could endanger every ship in formation. While line formation is ideal when a destroyer escort can be massed at each vulnerable flank point it is questionable whether this condition obtain when the escort is removed. In view of possible extension of submarine operations to distance further off share and to points beyond range of numerous destroyer escorts, question of the best convoy formation to foil attack when not escorted must be considered. Take this matter under advertisement. 22018. 7454.
Source Note: Cy, DNA, RG 45, Entry 517B. Document reference: “11-9-1P/1/3/C/K/J.”