Thread: [Traveller_TNE] Stupid Lasers

I have tried for the past two days to recreate the lasers that came in
the FF&S supplement and I cannot do it. I can't figure out how the
damned backpacks are so light. The 19.5 kg 50-shot backpack for the
TL8 laser carbine comes out too big and too costly by a factor of 10,
and the weapon is too light by a factor of about 3. I've checked and
double checked all the damned calculations, and I cannot get them any
closer.

This is one reason I've always hated laser design in FF&S. It's too
damned complicated -- more so than I think is required by simple game
mechanics.

Aaaargh!

Gerry Harris

http://www.aethertraveller.com

"Cry 'Havoc,' and let slip the dogs of war"
— Antony, "Julius Caesar," Act 3, Scene 1

--- Gerry Harris <> wrote:

> I have tried for the past two days to recreate the lasers that came in
> the FF&S supplement and I cannot do it. I can't figure out how the
> damned backpacks are so light. The 19.5 kg 50-shot backpack for the
> TL8 laser carbine comes out too big and too costly by a factor of 10,
> and the weapon is too light by a factor of about 3. I've checked and
> double checked all the damned calculations, and I cannot get them any
> closer.
>
> This is one reason I've always hated laser design in FF&S. It's too
> damned complicated -- more so than I think is required by simple game
> mechanics.
>
> Aaaargh!
>
>
>
The TL-8 Laser Carbine is incorrectly designed, probably because someone used a spreadsheet with
the wrong assumptions regarding batteries. AFAIK these are the correct values:

FA Diameter: 10 cm
Weapon Length: 68.3 cm
Pulse Discharge Energy: 0.01 MJ (Input Energy: 0.04 MJ, Power: 0.008 MW)
Weapon Specifications: 4.209 kg, Cr 1978
Power Pack Specifications: 50 Shots, 29.854 kg, Cr 115
Features: Laser Sight, Optic Sight, Ruggedised Body (Melee Standard....ok, so maybe I did a little
reinterpreting here, but then again this is supposed to be a FO weapon, and that seems to require
a lot of crawling through rock and bush)

One little thing to note here: FF&S creates a little too much confusion in the table for focal
array performance on page 127. It gives the impression that a grav focused laser is possible at TL
8 and 9, when in fact this option does not become available until TL-10. If you're trying to
recreate the TL-8 and 9 lasers in RCEG, you have to use the NON-Gravitic laser performance on page
126 to obtain the proper power requirement and use a non-grav focal array.

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On Thu, 5 Oct 2006 06:49:56 -0500, you wrote:

>It was the battery pack that was giving me fits. The rules don't make it
>clear what the discharge rate for such batteries are (I think I ended up
>using 50 small batteries of the ×125 output). As for output, what the
>insert gave as the weapon's damage was what I got for its "Thin Atmosphere"
>performance.

The discharge rate you need is something faster than the shortest time
the laser can empty the battery. If the laser fires once per turn and
has 50 shots (for example), it can empty the battery in 5 x 50 = 250
seconds, so you need to use a battery that can discharge faster than
that (ie a 36 second discharge battery). The battery's output needs to
be the total input energy of all the shots divided by the battery's
discharge time. So, if you example laser has an input energy of 0.05MJ
per shot, it has a total energy storage of 50 x 0.05 = 2.5MJ, and the
battery needs to be able to supply 2.5 / 36 = 0.07MW.

When it comes to gravitic focussing in small lasers, it's often simply
not worth it, as the cost in extra power means the battery weight is
prohibitive and you're better off simply using a bigger non-gravitic
lens. Another thing to watch is that at low TLs small gravitic lenses
are /worse/ than non-gravitic lenses. Also, the rules say that X-ray
lasers (available at TL13+) can only be made with heavy focal arrays,
which means they can't be used in smallarms, and IIRC this rules was
not observed in some of the official designs.
--
Rupert Boleyn <>

On 10/5/06, Rupert Boleyn <> wrote:
> On Thu, 5 Oct 2006 06:49:56 -0500, you wrote:
> >It was the battery pack that was giving me fits. The rules don't make it
> >clear what the discharge rate for such batteries are (I think I ended up
> >using 50 small batteries of the ×125 output). As for output, what the
> >insert gave as the weapon's damage was what I got for its "Thin Atmosphere"
> >performance.
>
> The discharge rate you need is something faster than the shortest time
> the laser can empty the battery. If the laser fires once per turn and
> has 50 shots (for example), it can empty the battery in 5 x 50 = 250
> seconds, so you need to use a battery that can discharge faster than
> that (ie a 36 second discharge battery). The battery's output needs to
> be the total input energy of all the shots divided by the battery's
> discharge time. So, if you example laser has an input energy of 0.05MJ
> per shot, it has a total energy storage of 50 x 0.05 = 2.5MJ, and the
> battery needs to be able to supply 2.5 / 36 = 0.07MW.

If you don't mind extrapolation of the battery output modifier I have
a convenient table (and the formula behind it) posted at
http://user.it.uu.se/~paho9211/trav/weapons/battmods.html

Calculate the minimum time required to empty the magazine at the
required RoF and find the output modifier for that time using the
table/formula. If you are designing a gauss weapon halve this value
(since the rules allow them to fire twice). Then just calculate power
input according to p130 in FFS and add a battery capable of supplying
enough juice (using the custom discharge rate/modifier). I use this
method for all battery powered weapons and I think it's much more
straightforward than the official one. It also helps to keep the
weight of batteries down especially for gauss weapons where the rules
assume a ~1 second discharge rate.

Patrik Holmström

On Fri, 6 Oct 2006 04:14:02 +0200, you wrote:

>If you don't mind extrapolation of the battery output modifier I have
>a convenient table (and the formula behind it) posted at
>http://user.it.uu.se/~paho9211/trav/weapons/battmods.html
>
>Calculate the minimum time required to empty the magazine at the
>required RoF and find the output modifier for that time using the
>table/formula. If you are designing a gauss weapon halve this value
>(since the rules allow them to fire twice).

They do? Where? I always assumed that gauss batteries were double the
weight they would otherwise be because you didn't have to allow weight
for the backpack and that their weight therefore included the
ruggesdization you need in a magazine.
--
Rupert Boleyn <>

On 10/8/06, Gerry Harris <> wrote:
>I used your table of battery discharge rates and it helped some.
However, I still
>cannot replicate the lasers in the Ire, Confusion & Raw Deal supplement. I'm
>beginning to think the designers A) didn't use the same design sequence as in
>the book, B) didn't double check their results, or C) both.

Are you talking about the lasers on p 354 in the main rule book? In
that case I'm pretty sure they where designed with a early version of
FFS or simply made up. IIRC someone confirmed that this was the case
for a couple of the vehicles in the book. I don't have the RC
equipment guide handy but I believe the designs in that book are
correct (except for the changes for fusion weapons from the Challange
#76/Striker II article "Putting the heat back into plasma").

> What I am going to end up doing is recreating every frickin' laser in the game just
> to have some consistency.

I hope you have a spreadsheet. :)

> Besides, it doesn't appear lasers are all that great personnel weapons anyway.
> They have no penetration against armored targets, and are relatively large and
> clumsy for the damage they do.

The main advantage of lasers IMO is their high hit probability.

Patrik Holmström

On 10/9/06, Rupert Boleyn <> wrote:
> On Fri, 6 Oct 2006 04:14:02 +0200, you wrote:
> >If you don't mind extrapolation of the battery output modifier I have
> >a convenient table (and the formula behind it) posted at
> >http://user.it.uu.se/~paho9211/trav/weapons/battmods.html
> >
> >Calculate the minimum time required to empty the magazine at the
> >required RoF and find the output modifier for that time using the
> >table/formula. If you are designing a gauss weapon halve this value
> >(since the rules allow them to fire twice).
>
> They do? Where? I always assumed that gauss batteries were double the
> weight they would otherwise be because you didn't have to allow weight
> for the backpack and that their weight therefore included the
> ruggesdization you need in a magazine.

It is a consequence of the ability of an high initiative characters to
act twice in a turn. Since gauss weapons are not rated with absolute
RoFs (e.g. SA3) the way energy weapons are (p 272, 2nd column, 2nd
paragraph) they must be able to fire at twice the "normal rate". This
makes sence since the weapons with RoF 5 in RL fires at around 10
rounds per second.

Patrik Holmström

----- Original Message -----

From:

To:

Sent: Monday, October 09, 2006 11:15 AM

Subject: RE: [Traveller_TNE] Stupid Lasers

I'm doing up personnel lasers. 

 

I wouldn't even attempt these blasted things without a spreadsheet.  I'm not even going to mess with "tunable" lasers.  I don't have the patience or the time.

---

From: [] On Behalf Of Patrik Holmstrom
Sent: Sunday, October 08, 2006 21:06
To:
Subject: Re: [Traveller_TNE] Stupid Lasers

On 10/8/06, Gerry Harris <> wrote:
>I used your table of battery discharge rates and it helped some.
However, I still
>cannot replicate the lasers in the Ire, Confusion & Raw Deal supplement. I'm
>beginning to think the designers A) didn't use the same design sequence as in
>the book, B) didn't double check their results, or C) both.

Are you talking about the lasers on p 354 in the main rule book? In
that case I'm pretty sure they where designed with a early version of
FFS or simply made up. IIRC someone confirmed that this was the case
for a couple of the vehicles in the book. I don't have the RC
equipment guide handy but I believe the designs in that book are
correct (except for the changes for fusion weapons from the Challange
#76/Striker II article "Putting the heat back into plasma").

> What I am going to end up doing is recreating every frickin' laser in the game just
> to have some consistency.

I hope you have a spreadsheet. :)

> Besides, it doesn't appear lasers are all that great personnel weapons anyway.
> They have no penetration against armored targets, and are relatively large and
> clumsy for the damage they do.

The main advantage of lasers IMO is their high hit probability.

Patrik Holmström