Sinking GEV's

I've decided to use the following as a house rule for GEVs:

No GEV with armour greater than 3 may cross water without sinking.

Sound reasonable?

If you use the same house rule for wheeled/tracked vehicles in mud,
marsh,
snow. Tires/Tracks sink in and get bogged down.

---
Brian Bell bbell1@insight.rr.com ICQ: 12848051 AIM: Rlyehable YIM: Rlyehable
The Full Thrust Ship Registry:
http://www.ftsr.org
---

[quoted original message omitted]

> At 10:48 AM -0400 10/18/01, Bell, Brian K (Contractor) wrote:

Then explain the variation in cross country mobility between the HVSS and VVSS
shermans of WWII. A larger vehicle with greater surface area on the supporting
structure will be able to better cross a given layer of ground.

Witness the use of Scorpions in the falklands campaign where the wheeled
vehicles were confined to roads.

I'm not saying that the rule is really a bad idea, just that perhaps you're
trying to add too much individual design complexity into a vehicle.

How about varying the amount of armour depending on whether its fast or slow
GEV?

> On 19-Oct-01 at 03:55, WJAL21@aol.com (WJAL21@aol.com) wrote:

I'm not sure what this would accomplish.

We once had a discussion here of the fact that the tanks in Hammer's Slammers
couldn't cross water because they would sink. I want to HR that affect so I
can use it in building scenararios. The two possible ways I can see going
about it are:

Any vehicle with more than X armour sinks.  I _believe_
the rules say that water craft may have no more than 3 armour so I used this
as the breakpoint. I haven't double checked the rules so it may be 2.

The other possibility was any vehicle that used more than 80% of its' space
would sink. This would make for designs only usable within our group and
didn't want that to occur.

The real catch is the thrust/weight ratio. The combat cars have enough
thrust to fly over water for short distances. The panzers must rely on the
ground effect
for lift and so will sink if the ground cannot support their weight -
like water or damaged bridges.

> On Fri, 19 Oct 2001, Roger Books wrote:

> On 19-Oct-01 at 03:55, WJAL21@aol.com (WJAL21@aol.com) wrote:

Another possible route you might take is this:

HR In order to move across water GEV's must be designed with the Amphibious
feature as for other land vehicles. GEV's built as amphibious may travel
across water as per normal rules. GEV's built without the amphibious
capability can for small rivers & streams, with the advantage that it is

easier terrain for them than for wheeled and tracked.

In this case, don't think of the "amphibious" feature as being just a
watertight hull and a couple of PTO proprllers, rather, it is a design feature
of the GEV which allows it's skirt & propellers to displace enough water
pressure to keep it from sinking.

Just a thought.

BrCB

"The Irish are the only race of people on Earth for which psychoanalysis is of
no use."

                                 - S. Freud

> From: Roger Books <books@jumpspace.net>

> On 19-Oct-01 at 12:14, Michael Llaneza (maserati@speakeasy.net) wrote:

I thought the combat cars could use ground effect to cross water.

If I remember Rolling Hot correctly, they had the thrust/weight ratio
needed to cross water, they did benefit from ground efefct but I cant think it
would be much of an added bonus.

> On Fri, 19 Oct 2001, Roger Books wrote:

> On 19-Oct-01 at 12:14, Michael Llaneza (maserati@speakeasy.net) wrote:

Can you imagine the waterspout that would (at least initially) create! I'm not
knocking the suggestion, but rather, I think it would be magnificent to watch
a GEV sidle into the water shooting plumes of steam

and waterspray hot enough to take the paint off of a '57 DeSoto

jim

> Brian Bilderback wrote:

> Another possible route you might take is this:

> the advantage that it is easier terrain for them than for wheeled and

> feature of the GEV which allows it's skirt & propellers to displace

> Roger Books wrote:

> > How about varying the amount of armour depending on

Nothing in DS2, since the tranny doesn't use up any explicit space inside the
vehicle.

> We once had a discussion here of the fact that the tanks

It is max Armour rating = 2 less than Vehicle Size Class (p.13). Makes
sense - the bigger a boat is, the thicker armour you can put on it. Same

goes for hovercraft, though since they are supposed to hover above the
water surface rather than half-way through it and thus don't displace as

much water they can't be as heavily armoured as boats.

(Yes, hovercraft do displace some water - though it is their air
cushions which do the displacing, not their hulls. This is usually visible on
pics of hovercraft moving over water.)

> Brian Bilderback (welcome back, BTW!) wrote:

> Another possible route you might take is this:
[...]
> In this case, don't think of the "amphibious" feature as being just a

Um, well. Put it like this: if you make the hull of an M1A2 Abrams completely
watertight and put propellers on it, it'll still sink. Even if you can keep
the volume straight above the tank free from water it'll eventually reach a
depth where the water pressure on its belly can support it; I did the
calculation a year or so back, but I don't remember
off-hand
if it was 25 feet or 25 meters below the surface...

IOW, if you want an amphibious GEV with heavy armour, you have to make it big
enough to spread the weight of that armour over a large enough surface so the
"ground pressure" of the vehicle is so low that the water can support it. This
is one of the DS2 vehicle design rules I actually agree

with <g>

Re: vehicle design system: I and Beth have made some progress over the past
year, but Beth has been more involved with FMA and I was side-tracked
into
FMA-izing the DS2 damage and to-hit systems. (The damage system was
posted
some weeks back - I think it is in the list archive by now <que:
Jerry>).

Later,

Michael actually used a misnomer here IIRC.

The Slammer's combat cars can generate enough lift with their fans to actually
create a ground effect cushion without the aid of the skirts. This is similar
to a helicopter which can do low altitude (very low) hovers at much lower
power than they can high altitude. Basically you're
sandwiching a cusion of air between the fans and the ground.   The hover
tanks (panzers) on the other hand can not generate sufficient lift to create
an air cushion without the aid of the plenum skirts due to their greater mass.

Bill
*************reply separator******************

                    Roger Books

<books@jumpspace.net> To:
gzg-l@CSUA.Berkeley.EDU
Sent by: cc:

                    owner-gzg-l@lists.CSUA.Be       Subject:     Re:
Sinking GEV's rkeley.EDU

                    10/19/01 12:01 PM

                    Please respond to gzg-l

> On 19-Oct-01 at 12:14, Michael Llaneza (maserati@speakeasy.net) wrote:

I thought the combat cars could use ground effect to cross water.

Roger

> Oerjan Ohlson wrote:

Remember you said this n a moment when I clarify my point.....

> Brian Bilderback (welcome back, BTW!) wrote:

Sorry if you took that comment literally. Let me clarify. To take a land
vehicle and make it amphibious, IRL, you have to make it displace enough

water to keep it afloat, and equip it with both land and water propulsion. In
the game, this is simulated by paying to make the vehicle amphibious.

Therefore:

> IOW, if you want an amphibious GEV with heavy armour, you have to make

Agreed. My suggestion is merely that since the way this is simulated for
ground vehicles in DSII is to pay for amphibious, it stands to reason that tis
is a viable way to simulate it in GEV's as well.

> Re: vehicle design system: I and Beth have made some progress over the

Sidetracked or no, I'd like to see what you have. I'll probably still stick
with my HR's, but I'm always willing to review and refine.

BrCB

BTW, Oerjan, thanks for the welcome.

Let me point out one other thing. I believe this discussion nicely highlights
one of the reasons I believe armor and amphibious capability should both cost
capacity. Let me explain regarding amphibiousness:

As I've discussed with Oerjan a year or more ago, vehicle CLASS represents
size, while CAPACITY represents a nebulous combination of mass and volume (not
all components of the same capacity will WEIGH the same amount or take up the
same amount of SPACE, but will all use up a relatively similar combined amount
of a vehicle's space and weight CAPACITY.

Amphibious vehicles, as stated, will essentially work under the same
principle as a boat - they float if they displace more water mass than
their own mass. Since class represents size, any two vehicles of the same
class will displace roughly the same amount of water. What makes one
amphibious and the other not is their comparative weight. The vehicle that
weighs less will float. To represent this in design, you reduce the amount the
vehicle can weigh, or it's CAPACITY. Thus, the CAPACITY cost for amphibious
should be class x (A), and represents the reduction in the amount of mass the
vehicle can carry and still float.

BrCB

"The Irish are the only race of people on Earth for which psychoanalysis is of
no use."

                                 - S. Freud

> From: "Brian Bilderback" <bbilderback@hotmail.com>

> past