How to Reduce Coaster
Intensity and Add Excitement
Greg Wolking & Steve Franks
The intensity rating of a coaster is
a measure of the effect of G-forces acting on its riders. While
higher G-forces make the ride more exciting, they also make it more
intense. If the G-forces get too high, the ride becomes more painful
than it is exciting. An intensity rating above 10 indicates a ride
that may either hurt or injure its riders. In fact, once the intensity
gets much above 10, the excitement rating takes a major nose-dive
as a consequence.
The actual G-force limits depend upon
the type of coaster, but generally speaking you want your maximum
positive vertical G's at 4 or below, maximum negative vertical G's
at -1.5 or above, and lateral G's at 2 or below. Some coaster types
will allow peaks above these limits as long as there aren't too
many of them and they're not spaced too closely together.
Steel Twister (and Vertical) coasters
have a very smooth ride, so they can usually tolerate G-forces from
.5 to 1 higher than listed above. Wooden coasters have much rougher
rides, so you will want your G-forces to be a bit lower. Coasters
with standing cars make your riders much more sensitive to both
lateral and vertical G-forces, so their upper limits are even lower,
especially for lateral G-forces.
Still other coasters (such as the inverted,
stand-up steel, and "flying" coasters) are more intense by their
very nature. Given identical layouts and G-forces with other similar
steel coasters, their overall intensity rating will be from 1 to
2 points higher. In other words, they start from a higher "base
If you want (or need) to reduce your
track's intensity rating, watch the G-force graphs as you test the
track to see where the peaks are. When you see a too-high peak in
the graph, pause the game and see where the train is (keeping in
mind that if you're running multiple trains, the graphs always follow
train 1), and thus where your track needs adjustment.
It's also important to realize that
it's not always the magnitude of the G-forces that make a ride too
intense. Almost every g-force "transition" adds to the intensity
of the ride, and the effect is cumulative. The more transitions
there are, and the more closely they occur, the more intense the
ride will be. Especially on longer, faster tracks, you may need
a few "boring" sections to allow your riders a chance to recover
from the pummeling they've taken in one section before you resume
pounding them in the next. You may even have to remove some drops
and/or inversions ("stunts") altogether. Yes, it's great fun to
build an ultra-mega-monster steel twister with 45 drops and 20 inversions,
but making such a coaster rideable is a formidable (if not impossible)
Common trouble spots:
- Flat turns where they could be
banked: Banking a turn
(given the same speed) shaves from between .5 to 1.5 off the lateral
G-forces (note that some coasters have steeper banks than others).
If the coaster does not allow banked turns, you must either use
a wider radius turn or do something to slow the train down (e.g.,
use trim brakes or move the turn to a higher elevation) before
it reaches the turn.
General guidelines to keep G-forces
reasonable for flat turns:
* Very small radius turns: 18 mph or less. These are only
found on the Wild Mouse coasters. Since sharp and violent turns
are expected on these coasters, you can get away with much higher
lateral G's than other coaster types. Therefore, you can take
a few of them at 20 to 22 mph without making the ride too intense,
especially if you have flat track to separate sharp turns in opposite
* Small radius turns: 20 mph or less, 25 to 30mph for a
Wild Mouse coaster.
* Normal radius turns: 30mph or less.
* Wide radius turns: 45mph or less.
* Ess-bends: 25mph or less, up to 30 mph with some coaster
types (e.g., wood and steel "twisters" and "suspended" coasters
with swinging cars).
An ess-bend behaves like two normal radius curves in opposite
directions in direct succession, so you have a sharp "G-reversal"
in the middle. Don't use more than one ess-bend in direct succession
if you don't have to, unless the train is moving fairly slowly
(20mph or less.) If both ess-bends are in the same direction,
consider substituting a pair of wide radius turns in opposite
directions to make a single "wide-ess". This will give you the
same lateral shift (2 tiles) in the same distance (6 tiles), but
the wider turns produce lower lateral G's overall and only one
reversal in the middle.
- Vertical loops & half-loops taken
too fast: Generally speaking, you do not want a train to be
going much over 40mph when its head reaches the base of the loop.
Alternatively, keep the speed between 12 to 20mph as the train
crests the loop. Steel Twister coasters can tolerate a bit more
speed here. Tuning loops takes practice as you have to balance
the need for enough speed to get through the loop at all against
taking it so fast the G-forces are too high. Also note that too
slow through a loop can be just as bad as too fast. Too slow (less
than 10mph at the top) not only has the riders hanging upside
down from the restraints, it can lead to stalls and subsequent
- Corkscrews taken too fast:
These are even tougher to tune than vertical loops because they
produce a very sharp lateral-G spike at their entrance, and the
speed difference between fast enough to make it over the top and
too fast to keep the G-forces tolerable is much closer than a
vertical loop. In most cases, you do not want to enter a corkscrew
at much over 30mph, but usually you need at least 27 to 28 mph
to make it through the stunt at all. WARNING: Avoid using trim
brakes immediately before the entrance to a corkscrew. The random
variance involved with trim brakes can lead to stalls and subsequent
Combinations of half-loops and corkscrews such a Cobra Roll, Batwing,
or Butterfly take very careful tuning to keep them from being
too intense. You definitely do not want to come out the base of
a vertical loop (or half-loop) and go directly into a corkscrew.
If the train is fast enough to get through the loop, it will hit
the corkscrew at or near 40 mph, and that will put the lateral
G's through the roof.
- Barrel rolls & inline twists:
Try to enter these at 25mph or less, up to 30mph for a Steel Twister.
Also, note that if you enter these particular stunts immediately
after a banked turn, you can make them less intense by choosing
the proper direction for the roll/twist. That is, after the train
banks out of the turn, it should continue to bank in the same
direction as it enters the roll/twist, so make the twist in the
opposite direction of the turn.
- Camel Humps: (i.e., hills
with steep-slope approaches and departures) with the top of the
hill too low. Except for the steel twister, you generally do not
want your train to crest a Camel Hump (or dive downward from flat
track into a steep slope) at much over 25mph, or the negative
vertical G's will be too high. You also want to avoid too many
Camel Humps in direct succession. If possible, vary things a bit...use
a normal slope on one side of a hill, and a steep slop on the
other, etc. Rides that do the same thing over and over and over
again are often very boring (although they may still produce decent
numbers in RCT.)
- Too many opposite G-forces in
direct succession: This includes both too many turns in opposite
directions in direct succession, and too many up/down slope transitions
in direct succession. If possible, add some flat track in between
to give your riders time to "settle" before the forces reverse
direction instead of slamming them repeatedly from one side of
the car to the other, or alternately mashing their butts against
the seats and bruising their thighs on the lap bars. Again, the
more modern coasters with smoother rides will tolerate more of
this than older, rougher coasters, but there is still a limit.
- Do not come screaming into the
station: Not only is this hell on the station brakes (leaving
you prone to the deadly station brake failure crash), but the
sudden stop makes the ride much more intense. By the same token,
when you do need to slow the train with track brakes, do it gradually.
You do not want a train barreling along at 45mph+ to hit a row
of 18mph brakes! Instead, graduate the individual brake speeds
so the train is slowed in stages. Generally speaking, no more
than two "levels" (9mph) from one set of brakes to the next.
- Be careful of sudden slope transitions:
Where coasters allow it (Steel Mini, Wild Mouse, and Vertical),
be very careful with direct transitions from flat track to a steep
slope. These can be quite effective on a Wild Mouse (and a nice
way to get a Steel Mini rolling quickly at the top of the initial
lift), but you still have to keep the speed down or the vertical
G's will go though the roof. Also watch out for "staggered" slopes
that change from normal to steep (and vice-versa) in the middle.
A normal-to-steep transition produces a sharp positive/negative
G peak. Your layout may require you to use a combination of slopes
to get the track to the proper elevation, so try to put those
transitions as close to the top of the slope as possible, where
the train is moving the slowest.
- Too many drops: Drops (when
taken fast enough) produce negative vertical G's or "air time",
and thus help make the ride more exciting. However, all but the
very slowest drops add to the ride's intensity. The effect is
cumulative, so too many drops can make the ride too intense, even
if the G-forces are within acceptable limits throughout the entire
run. Therefore, tuning a track may require reducing the number
of drops, including replacing "staggered" short drops with a single
long drop, or (when possible) replacing a drop with a downward
- Use "steep twist" sections judiciously.
The "steep twist" segment available with some coasters is a handy
tool for creating compact layouts because it lets you perform
a 90-degree turn within one tile, just like the "very small radius"
flat turns available on "wild mouse" coasters. However, these
steep twists produce very high lateral G's just like their flat
counterparts. Therefore, you want to use those segments at the
highest point possible on the slope, where the train is moving
slowest. Also, on downward steep slopes, the train accelerates
very quickly, so you can rarely get away with more than two steep
twists (i.e., a 180-degree turn) in succession. Successive steep
twists in opposite directions almost always make the ride too
intense because of the sudden "G-reversal" in the middle.
- Roll-out/Roll-in: Many tracks
will have banked turns in the same direction with a short straight
(2 to 5 segments) between them. The natural tendency is to roll
out of one turn onto flat track, then roll into the next. However,
rolling into and out of banks produces vertical-G "bumps" as one
side of the train lifts up into the bank and drops down out of
the bank. If the train is moving very fast (50mph or more) at
that point, consider keeping the track banked throughout the straight
portion. Admittedly, this is not a major effect, but when you're
tuning a really big, really fast coaster, every point you can
shave off the intensity rating helps.
original articles have been transcribed and illustrated by Steve
Franks for exclusive use at RCT Station, and are posted with the
permission of Greg Wolking.