Emergency Beacon Detection Range

ottarrus said:
Radio waves emit in the 360 degrees, even directional radar signals. If you emit a radio signal, you're emitting 'in the round' so to speak. A directional transmitter greatly increases the signal strength along the transmission axis, but it should not be forgotten that you're transmitting in a circle.
This is why Traveller specifically differentiates 'tightbeam' signals via laser or meson beam.
Click to expand...
Any emission in the round would be a side effect of a directed signal (not necessarily just radio, but even radio waves can be reflected therefore made directional). More important is a directed receiver and that is difficult to achieve unless you know where the signal is coming from (and if you knew that you wouldn't need the signal).

Whether the pod has incidental transmission in other directions is irrelevant to the receiving array, anything not pointed at it is wasted energy. If the concept of operations is not a net of SAR vessels floating about in la la space "just in case" then no-one else is going to pick those signals up in time to be useful either. You could have a multitude of repeater drones but the money for infrastructure needed would probably be better spent on hospitals as you would save more lives per credit.
 
CordwainerFish said:
Oh, it is a lot more complicated than that.

dammit link why won't you be blue like God and Tim Berners-Lee intended
Click to expand...
Oh, I completely agree that it's a lot more complicated than my description.
I'm only stating the simple physics as they relate to a gaming table, rather than a peer reviewed journal article. EVERYTHING we discuss in Traveller, especially technology, is more detailed than the rulings at the table a referee makes. Traveller tries very hard to keep physics in the game with comparatively few 'magic technologies', but it also tries to keep the physics simple enough to move the game along.
 
Terry Mixon said:
As an example of why even old signals might matter, here is an escape pod that has 15 people and can last for over two decades. Adventure fodder, there.

View attachment 4978
Click to expand...
So no manoeuvre ability at all other than inherited velocity from the ship and any from the ejection.

No adventure really other than you wake up somewhere random after n years or you don't wake up at all.

Is power all you need? Low berths require Cr100 of consumables per month in life support. This is not power (since that is effectively free). If these consumables are just Cr50 of drugs, nutritional supplements etc. when initially "frozen" or when revived this won't be an issue. If even low passengers require minimal air (such as if fast drugged) then cost and tonnage needs to be allowed and a 20 year supply would soon add up (a biosphere could offset this).

Who is conducting the monthly maintenance. After a single year you will have missed 12 maintenance cycles and are guaranteed to have suffer a critical hit (though arguably only a roll of 2-4 and 10-12 on the table would have any effect). Every month after would also be a guaranteed hit. I would suggest a cheap droid would be needed but there is also the question of spares..

BUT since the pod isn't actually capable of moving, you might be better treating the pod as a vacuum protected robot with an autodoc/low berth as an internal component. You can then also take the low maintenance options and either a lot of power packs or an RTG (solar is a bit risky). There is no indication of the power a cryoberth uses but given a low berth only requires 1/10 power I am sure the RTG could manage.

Frankly a default grav low berth with a retrofitted RTG would probably do and could last longer (and there would be no moral dilemma since each pod has it's own power). A grav berth could actually land on a planet (if it happened by one) given enough time.

I would probably go for a much smaller pod (2 ton) with a single low berth which leave 1.5 Dtons for other components. As the only power requirement is the low berth which is 1/10 and 1/10 for the non-gravitic hull power, which can be generated by 1/50th of a Ton of TL8 fusion plant costing KCr10. 1 DTon of fuel would last that plant 1000 weeks (almost 20 years) but there is no reason not to fill all the remaining space (1.48 in total) with fuel as well and extend it out to 28 years. With the money you save on the Sterling plant you can buy a maintenance droid with skills in Powerplant repairs and maintenance (maybe sacrifice a bit of fuel for maintenance access). Sending a 1 second ping every hour for 20 years won't use much power (and you can run the ships systems at half power dropping your power usage to 3/20th of a power unit most of the time). It all comes to under KCr200 fuelled, the Cr50 life support prepaid and including a Standard Engineering Droid according to my calculations.
 
swordtart said:
So no manoeuvre ability at all other than inherited velocity from the ship and any from the ejection.

No adventure really other than you wake up somewhere random after n years or you don't wake up at all.

Is power all you need? Low berths require Cr100 of consumables per month in life support. This is not power (since that is effectively free). If these consumables are just Cr50 of drugs, nutritional supplements etc. when initially "frozen" or when revived this won't be an issue. If even low passengers require minimal air (such as if fast drugged) then cost and tonnage needs to be allowed and a 20 year supply would soon add up (a biosphere could offset this).

Who is conducting the monthly maintenance. After a single year you will have missed 12 maintenance cycles and are guaranteed to have suffer a critical hit (though arguably only a roll of 2-4 and 10-12 on the table would have any effect). Every month after would also be a guaranteed hit. I would suggest a cheap droid would be needed but there is also the question of spares..

BUT since the pod isn't actually capable of moving, you might be better treating the pod as a vacuum protected robot with an autodoc/low berth as an internal component. You can then also take the low maintenance options and either a lot of power packs or an RTG (solar is a bit risky). There is no indication of the power a cryoberth uses but given a low berth only requires 1/10 power I am sure the RTG could manage.

Frankly a default grav low berth with a retrofitted RTG would probably do and could last longer (and there would be no moral dilemma since each pod has it's own power). A grav berth could actually land on a planet (if it happened by one) given enough time.

I would probably go for a much smaller pod (2 ton) with a single low berth which leave 1.5 Dtons for other components. As the only power requirement is the low berth which is 1/10 and 1/10 for the non-gravitic hull power, which can be generated by 1/50th of a Ton of TL8 fusion plant costing KCr10. 1 DTon of fuel would last that plant 1000 weeks (almost 20 years) but there is no reason not to fill all the remaining space (1.48 in total) with fuel as well and extend it out to 28 years. With the money you save on the Sterling plant you can buy a maintenance droid with skills in Powerplant repairs and maintenance (maybe sacrifice a bit of fuel for maintenance access). Sending a 1 second ping every hour for 20 years won't use much power (and you can run the ships systems at half power dropping your power usage to 3/20th of a power unit most of the time). It all comes to under KCr200 fuelled, the Cr50 life support prepaid and including a Standard Engineering Droid according to my calculations.
Click to expand...
Your points are valid. The AutoBerths are robotic and have built in medics. Adding self-maintenance is doable and a good idea. I made a version that was 3 tons and dual persons. The fission plant was 2 tons minimum so I had the space for the second.

EDIT: Checked the self-maintenance option for x24 that would cover things. That is hella expensive. Adds millions to the cost of each AutoBerth. Has to have it, but wow.

1748639777686.png
 
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Terry Mixon said:
Your points are valid. The AutoBerths are robotic and have built in medics. Adding self-maintenance is doable and a good idea. I made a version that was 3 tons and dual persons. The fission plant was 2 tons minimum so I had the space for the second.

View attachment 4979
Click to expand...
I'm still not sure why you went with the special drive.
You only need 0.1 per per berth, which would make 0.3 total plus 20% of 5 tons for the hull (which is halved for the non-gravitic hull and halved again if you "do without the coffee machines"). Most of the time you are using less than 0.6 power and in those circumstances even the low tech conventional fission plants are far more space efficient, even when you add in the fuel requirement. Since you are operating at TL15 you only need 1/36th of a ton of plant (KCr55) and 1/360th of a ton of fuel will last 2 weeks. For your 2 tons of Sterling plant you could last over 27 years without difficulty.
You could leave everything else unchanged on the design and still bring the price down by over a MCr.
 
swordtart said:
I'm still not sure why you went with the special drive.
You only need 0.1 per per berth, which would make 0.3 total plus 20% of 5 tons for the hull (which is halved for the non-gravitic hull and halved again if you "do without the coffee machines"). Most of the time you are using less than 0.6 power and in those circumstances even the low tech conventional fission plants are far more space efficient, even when you add in the fuel requirement. Since you are operating at TL15 you only need 1/36th of a ton of plant (KCr55) and 1/360th of a ton of fuel will last 2 weeks. For your 2 tons of Sterling plant you could last over 27 years without difficulty.
You could leave everything else unchanged on the design and still bring the price down by over a MCr.
Click to expand...
The fuel requirements for fission is 10.4 tons for a 3-ton hull and only allocating .3 power for twenty years (1,040 weeks) before it starts failing and another five years (260 weeks) before the occupants perish. That's a total of 25 years (1,300 weeks). 13 tons of fuel for the entire time. The Sterling has no fuel requirement and can fit in the small space.
 
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swordtart said:
So no manoeuvre ability at all other than inherited velocity from the ship and any from the ejection.

No adventure really other than you wake up somewhere random after n years or you don't wake up at all.

Is power all you need? Low berths require Cr100 of consumables per month in life support. This is not power (since that is effectively free). If these consumables are just Cr50 of drugs, nutritional supplements etc. when initially "frozen" or when revived this won't be an issue. If even low passengers require minimal air (such as if fast drugged) then cost and tonnage needs to be allowed and a 20 year supply would soon add up (a biosphere could offset this).

Who is conducting the monthly maintenance. After a single year you will have missed 12 maintenance cycles and are guaranteed to have suffer a critical hit (though arguably only a roll of 2-4 and 10-12 on the table would have any effect). Every month after would also be a guaranteed hit. I would suggest a cheap droid would be needed but there is also the question of spares..

BUT since the pod isn't actually capable of moving, you might be better treating the pod as a vacuum protected robot with an autodoc/low berth as an internal component. You can then also take the low maintenance options and either a lot of power packs or an RTG (solar is a bit risky). There is no indication of the power a cryoberth uses but given a low berth only requires 1/10 power I am sure the RTG could manage.

Frankly a default grav low berth with a retrofitted RTG would probably do and could last longer (and there would be no moral dilemma since each pod has it's own power). A grav berth could actually land on a planet (if it happened by one) given enough time.

I would probably go for a much smaller pod (2 ton) with a single low berth which leave 1.5 Dtons for other components. As the only power requirement is the low berth which is 1/10 and 1/10 for the non-gravitic hull power, which can be generated by 1/50th of a Ton of TL8 fusion plant costing KCr10. 1 DTon of fuel would last that plant 1000 weeks (almost 20 years) but there is no reason not to fill all the remaining space (1.48 in total) with fuel as well and extend it out to 28 years. With the money you save on the Sterling plant you can buy a maintenance droid with skills in Powerplant repairs and maintenance (maybe sacrifice a bit of fuel for maintenance access). Sending a 1 second ping every hour for 20 years won't use much power (and you can run the ships systems at half power dropping your power usage to 3/20th of a power unit most of the time). It all comes to under KCr200 fuelled, the Cr50 life support prepaid and including a Standard Engineering Droid according to my calculations.
Click to expand...
The robot rules only let me build a one-ton robot. Anything bigger is a vehicle. Which, I admit, I didn't consider. The spreadsheet says the fuel requirement is significantly higher than your estimate.

I can add a maintenance robot to handle the powerplant.
 
Updated for a long duration robot to do maintenance and adding self-maintenance to the AutoBerths. Figured out that I could add more power (up to 12) to the Sterling without raising the cost or size.

Edit: I bumped the life of the pod to 33 years so I need to bump the self-maintenance level on the AutoBerth and the maintenance robot, too.

Actually, it would be cheaper to add an extra robot just let the two robots work on one another and the AutoBerths without the extended lifespan packages. Continued reliable operations requires 0.1% of the robot’s cost per year in spares and diagnostic checks. That’s a lot cheaper than self-maintenance enhancements.

1748654285540.png
 
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Terry Mixon said:
The fuel requirements for fission is 10.4 tons for a 3-ton hull and only allocating .3 power for twenty years (1,040 weeks) before it starts failing and another five years (260 weeks) before the occupants perish. That's a total of 25 years (1,300 weeks). 13 tons of fuel for the entire time. The Sterling has no fuel requirement and can fit in the small space.
Click to expand...
I am not sure where my maths has gone wrong?

For your new design.

2 low berth requires 0.2 power
Hull power requirement is 20% of hull in DTons so a 3 ton hull requires 0.6 power, non-gravity makes that 0.3 and running on half power (which can be default since you have no crew) makes 0.15. Arguably even that could be reduced to zero as the ship doesn't even need basic life support, but we'll keep it as we will need to charge the droids up occasionally.

Total Power Requirement = 0.35

TL15 fission plant = 20 power per DTon.

Plant required is 0.35 / 20 = 0.0175 DTons

Fuel for a fission plant is 10% of the plant tonnage per 2 weeks. = 0.00175 DTons per 2 weeks

1.92 Dton for the Sterling plant minus the 0.0175 for the fission plant leaves 1.9025 DTons for fuel if you go TL15 Fission instead of Sterling.

1.9025 / 0.00175 = 1087 x 2 weeks = 2174 weeks = 41 years.

Is your spreadsheet correct?

EDIT:
I tried using the spreadsheet (2025.05.13) and I can't put in a Hull tonnage below 5 (I am not sure if there is a validation settings override somewhere). I would always prefer these things to throw warnings rather than prohibit certain values but that is a design choice.

On the Power Plant tab, the calculation for required power rounds the power requirement up to 1. This is not a thing as far as I know and whilst normally would not be an issue, it is potentially a problem for small craft. However as you can manually enter the required power at D11 this is not such an issue.

There is a rounding annoyance at D11 as if you put 0.35 (for example) into that field the the rounding shows it as 0 (it is correct in the formula breakout section at the top). However it seems to round the power plant tonnage to 2 decimal places putting the plant size at 0.02 rather than 0.0175.

The worst error however is in the fuel calculation, as it shows the fuel requirement (at H10) for 2 weeks as 0.02 rather than 0.00175 (10% of the tonnage of the plant) or maybe 0.002 as it seems to carry the rounding over from the Power Plant tab rather than just being in the display field. Changing the power of the plant doesn't give a linear increase in the fuel requirement (as it should) so there is something very out of whack here. For example making the power requirement 1, correctly shows the TL15 plant as taking 0.05 DTons. The fuel for two weeks however is shown as 0.02 tons rather than the 0.005 it should be. Set the power requirement to 20 and the plant correctly shows 1.0 Dton but the fuel requirement for 2 weeks is 0.06 DTons whereas it should be 0.1 DTon.

Without being able to see the code under the bonnet I can't diagnose further, but the spreadsheet appears to need some correction. If all your designs are based on it, they may also need revisiting. It is easy to see for example that the 95 Ton Shuttles should require 0.59 DTon of fuel vs. the 0.32 DTon shown. Where you have used reduced fuel jump drives the delta is less obvious, but the Awl-Class needs 7.72 more DTons fuel to achieve the required 16 weeks operation (as it stands it can achieve just over 8).
 
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swordtart said:
I am not sure where my maths has gone wrong?

For your new design.

2 low berth requires 0.2 power
Hull power requirement is 20% of hull in DTons so a 3 ton hull requires 0.6 power, non-gravity makes that 0.3 and running on half power (which can be default since you have no crew) makes 0.15. Arguably even that could be reduced to zero as the ship doesn't even need basic life support, but we'll keep it as we will need to charge the droids up occasionally.

Total Power Requirement = 0.35

TL15 fission plant = 20 power per DTon.

Plant required is 0.35 / 20 = 0.0175 DTons

Fuel for a fission plant is 10% of the plant tonnage per 2 weeks. = 0.00175 DTons per 2 weeks

1.92 Dton for the Sterling plant minus the 0.0175 for the fission plant leaves 1.9025 DTons for fuel if you go TL15 Fission instead of Sterling.

1.9025 / 0.00175 = 1087 x 2 weeks = 2174 weeks = 41 years.

Is your spreadsheet correct?

EDIT:
I tried using the spreadsheet (2025.05.13) and I can't put in a Hull tonnage below 5 (I am not sure if there is a validation settings override somewhere). I would always prefer these things to throw warnings rather than prohibit certain values but that is a design choice.

On the Power Plant tab, the calculation for required power rounds the power requirement up to 1. This is not a thing as far as I know and whilst normally would not be an issue, it is potentially a problem for small craft. However as you can manually enter the required power at D11 this is not such an issue.

There is a rounding annoyance at D11 as if you put 0.35 (for example) into that field the the rounding shows it as 0 (it is correct in the formula breakout section at the top). However it seems to round the power plant tonnage to 2 decimal places putting the plant size at 0.02 rather than 0.0175.

The worst error however is in the fuel calculation, as it shows the fuel requirement (at H10) for 2 weeks as 0.02 rather than 0.00175 (10% of the tonnage of the plant) or maybe 0.002 as it seems to carry the rounding over from the Power Plant tab rather than just being in the display field. Changing the power of the plant doesn't give a linear increase in the fuel requirement (as it should) so there is something very out of whack here. For example making the power requirement 1, correctly shows the TL15 plant as taking 0.05 DTons. The fuel for two weeks however is shown as 0.02 tons rather than the 0.005 it should be. Set the power requirement to 20 and the plant correctly shows 1.0 Dton but the fuel requirement for 2 weeks is 0.06 DTons whereas it should be 0.1 DTon.

Without being able to see the code under the bonnet I can't diagnose further, but the spreadsheet appears to need some correction. If all your designs are based on it, they may also need revisiting. It is easy to see for example that the 95 Ton Shuttles should require 0.59 DTon of fuel vs. the 0.32 DTon shown. Where you have used reduced fuel jump drives the delta is less obvious, but the Awl-Class needs 7.72 more DTons fuel to achieve the required 16 weeks operation (as it stands it can achieve just over 8).
Click to expand...
Code under the bonnet: The password is Password.
 
Not at the computer this moment but rather than a ship, the escape pod is a pod. The Ship Info tab has that selector and can be changed from ship to pod there. Pods are not ships, so no drives and no minimum size. They are reverse engineered from the element class cruisers.

The lower fuel requirements for small craft come from the small craft catalog, I believe. I’ll now read what you said in detail.

Arkathan is the designer and maintainer of the sheet and if the calculations are wrong, I’ll have a lot of work to do so I hope they aren’t. ;)
 
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Terry Mixon said:
Not at the computer this moment but rather than a ship, the escape pod is a pod. The main tab (I think) is two to the right of the Summary tab and can be changed there. Pods are not ships, so no drives and no minimum size. They are reverse engineered from the element class cruisers.

The lower fuel requirements for small craft come from the small craft catalog, I believe. I’ll now read what you said in detail.

Arkathan is the designer and maintainer of the sheet and if the calculations are wrong, I’ll have a lot of work to do so I hope they aren’t. ;)
Click to expand...
Since the calculations come from HG, there should only be rounding errors, brought on by trying to make things smaller than the HG limits, with gear HG didn't initially include.
 
Arkathan said:
Since the calculations come from HG, there should only be rounding errors, brought on by trying to make things smaller than the HG limits, with gear HG didn't initially include.
Click to expand...
Swordtart mentioned checking my Awl system defense boat, so it is a regular ship, perhaps not vs just a 3-ton pod. That said, the fuel calculations have been on target for recreating book designs (including small craft), so I’m skeptical.
 
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