About Battery Bank Layout

Recently I have come across a battery Bank Layout.This set up is new to me and I have not seen such till date. The specification of cell (battery) is " Valve Regulated Lead Acid ( VRLA)-Maintenance Free Battery-Having Electrolyte Confirming to :IS 266 (H2SO4)-Gas Generation for Single Cell=6.6 cc/cell/Hr-Gassification Voltage per cell=2.4 V/cell.It is 220 V/1500 AMPHr rated total cells=108 Nos.These batteries are filled with acid and charged( ready to use).What surprised me is the installation of each battery as each battery is installed in horizontal configuration ( the terminals and the hole plugs are kept horizontally and connected through copper strips/cables(inter stack). Total 108 batteries are put in 3-Nos of stacks (40+32+36) and all batteries are kept horizontally.I would like readers view whether this configuration( Horizontal laying of batteries) is correct.As I have always seen The Umbrella mark on battery pack-to be kept always upright. How the gases will come out as the electrolyte would cover the hole plug,what about leakage.Whether this configuration is correct or new technology of installing batteries?