﻿Manufacturers 
  generally 
  rate 
  the 
  capacity 
  of 
  lifts 
  and 
  tows 
  in 
  "skiers 
  per 
  hour" 
  

   or 
  "rides 
  per 
  hour." 
  Such 
  figures, 
  however, 
  are 
  not 
  additive 
  because 
  a 
  "ride" 
  at 
  one 
  

   area 
  may 
  be 
  much 
  shorter 
  than 
  a 
  "ride" 
  at 
  another 
  ski 
  area. 
  Because 
  of 
  the 
  differences 
  

   in 
  length 
  of 
  lifts, 
  the 
  ride 
  capacity 
  figure 
  is 
  peculiar 
  to 
  each 
  ski 
  lift 
  or 
  tow. 
  In 
  effect, 
  

   lifts 
  and 
  tows 
  have 
  a 
  machine 
  capacity 
  to 
  haul 
  skiers 
  to 
  the 
  top 
  of 
  a 
  certain 
  ski 
  hill 
  at 
  a 
  

   certain 
  rate 
  of 
  speed. 
  However, 
  the 
  actual 
  number 
  of 
  skiers 
  the 
  ski 
  area 
  can 
  accommo- 
  

   date 
  during 
  a 
  given 
  day 
  depends 
  on 
  skier 
  behavior. 
  If 
  each 
  skier 
  took 
  only 
  one 
  ride 
  a 
  

   day, 
  the 
  manufacturer's 
  rating 
  in 
  skiers 
  per 
  hour 
  would 
  be 
  adequate. 
  But 
  skiers 
  seldom, 
  

   if 
  ever, 
  are 
  willing 
  to 
  travel 
  to 
  a 
  ski 
  area 
  for 
  a 
  single 
  ride. 
  Depending 
  on 
  their 
  skill, 
  

   the 
  length 
  and 
  steepness 
  of 
  the 
  hill, 
  the 
  number 
  of 
  other 
  skiers, 
  weather 
  conditions, 
  and 
  

   other 
  factors, 
  they 
  may 
  take 
  as 
  many 
  as 
  30 
  or 
  40 
  rides 
  or 
  as 
  few 
  as 
  5 
  or 
  6 
  rides 
  during 
  

   a 
  day. 
  The 
  "average 
  skier" 
  probably 
  takes 
  a 
  different 
  number 
  of 
  rides 
  at 
  each 
  area 
  

   because 
  of 
  these 
  variations 
  . 
  

  

  The 
  none 
  ompar 
  ability 
  of 
  capacity 
  stated 
  in 
  skiers 
  per 
  hour 
  is 
  illustrated 
  by 
  the 
  

   following 
  example: 
  Ski 
  area 
  X 
  has 
  a 
  lift 
  with 
  a 
  rated 
  capacity 
  of 
  1, 
  000 
  skiers 
  per 
  hour 
  

   while 
  ski 
  area 
  Y's 
  lift 
  is 
  rated 
  at 
  only 
  500 
  skiers 
  per 
  hour. 
  On 
  the 
  surface 
  it 
  appears 
  

   that 
  X 
  has 
  twice 
  as 
  much 
  capacity 
  as 
  Y 
  and 
  should 
  be 
  able 
  to 
  serve 
  twice 
  as 
  many 
  skiers 
  

   in 
  a 
  day. 
  However, 
  area 
  X 
  has 
  a 
  500-foot 
  vertical 
  rise, 
  and 
  Y 
  has 
  a 
  1,000-foot 
  vertical 
  

   rise. 
  Skiers 
  at 
  area 
  X 
  are 
  transported 
  a 
  much 
  shorter 
  distance 
  than 
  skiers 
  at 
  area 
  Y. 
  

   The 
  same 
  skier 
  will 
  want 
  more 
  rides 
  per 
  day 
  at 
  X 
  than 
  at 
  Y 
  because 
  he 
  skies 
  a 
  shorter 
  

   distance 
  down 
  after 
  each 
  ride 
  and 
  will 
  be 
  less 
  tired 
  after 
  one 
  run 
  at 
  X 
  than 
  he 
  would 
  at 
  

   Y. 
  It 
  is 
  possible 
  that 
  one 
  skier 
  might 
  take 
  twice 
  as 
  many 
  runs 
  at 
  X 
  as 
  he 
  would 
  at 
  Y, 
  

   because 
  the 
  vertical 
  rise 
  is 
  twice 
  as 
  great 
  at 
  Y. 
  In 
  either 
  case, 
  the 
  skier 
  would 
  have 
  

   traveled 
  the 
  same 
  number 
  of 
  vertical 
  feet. 
  K 
  the 
  skier 
  at 
  area 
  X 
  takes 
  10 
  rides 
  on 
  the 
  

   500-foot 
  lift, 
  he 
  has 
  traveled 
  5,000 
  vertical 
  feet, 
  the 
  same 
  as 
  the 
  skier 
  at 
  Y 
  who 
  took 
  

   only 
  5 
  rides 
  on 
  a 
  l,OOO^oot 
  hill. 
  

  

  By 
  multiplying 
  the 
  rated 
  capacity 
  of 
  skiers 
  per 
  hour 
  by 
  the 
  vertical 
  rise, 
  we 
  can 
  

   express 
  lift 
  and 
  tow 
  capacity 
  measure 
  that 
  is 
  additive 
  and 
  allows 
  comparison 
  of 
  dif- 
  

   ferent 
  lifts 
  and 
  areas. 
  In 
  the 
  example 
  above, 
  both 
  areas 
  X 
  and 
  Y 
  have 
  equal 
  capacity. 
  

   (Area 
  X: 
  1,000 
  skiers 
  per 
  hour 
  X 
  500 
  vertical 
  feet 
  = 
  500,000 
  Vertical 
  Transport 
  Feet 
  

   (VTF) 
  per 
  hour. 
  Area 
  Y: 
  500 
  skiers 
  per 
  hour 
  X 
  1, 
  000 
  vertical 
  feet 
  = 
  500, 
  000 
  VTF 
  

   per 
  hour.) 
  

  

  Lifts 
  are 
  run 
  at 
  less 
  than 
  optimum 
  speed 
  because 
  the 
  skiers 
  can't 
  move 
  from 
  the 
  

   waiting 
  line 
  into 
  the 
  loading 
  position 
  quickly 
  enough. 
  This 
  may 
  be 
  due 
  to 
  skier 
  inexperi- 
  

   ence, 
  poor 
  ramp 
  design, 
  or 
  both. 
  Weather 
  problems 
  of 
  wind 
  also 
  force 
  the 
  operator 
  to 
  

   run 
  the 
  lift 
  or 
  tow 
  at 
  something 
  less 
  than 
  maximum 
  safe 
  speed. 
  For 
  these 
  reasons 
  

   VTF/hr. 
  capacity 
  was 
  calculated 
  on 
  the 
  basis 
  of 
  the 
  operators' 
  estimated 
  actual 
  opera- 
  

   ting 
  rate 
  of 
  skiers 
  per 
  hour 
  rather 
  than 
  the 
  manufacturers' 
  rated 
  capacity 
  of 
  skiers 
  per 
  

   hour 
  , 
  

  

  39 
  

  

  