Definition; A tugboat (tug) is a boat that maneuvers vessels by pushing or towing them.
The post is about using smaller ships to assist Freighters into warp. It is not immunity nor is it safe. If you are not doing this with an alt or someone you have long established trust - then seriously consider a courier contract.
The core of the process is, when a freighter has jumped through a gate and is aligning to the next gate, applying two webs will cause the freighter to near instant warp. To best of my knowledge - which is my no means all encompassing - it only works then.
This is the ideal. You can use a Condor or Slasher similarly fitted. (they both have four mid slots). The bonuses to web ranges are what we are seeking. But with 30km ranged (non-faction) webs, you are quicker off the mark to web the freighter. There are other ships with the range bonus (such as the minmatar recons). But the Hyena is faster, more manoeuvrable and quicker to train into.
Might be better if I just list out the process, then the fit might make more sense.
I can and have done this with a two ship fleet, squad command does not matter to either ship.
Fleet up and all pilots check that they have same route listed. Then check through the map stats for kills with the hour. If there is a large red along the route - then consider deferring the operation.
The tug will need an overview set only for fleet members.
The tug undocks and uses the MWD to create a distance over 150km. For a busy trade hub like Jita or Amarr, consider unto 1000km or more. If you have a third person for a scout then use them. The freighter then undocks and warps to tug. Should happen quickly. When the freighter reaches the tug, you need to initiate a duel. Which makes it work regardless of being in the same corporation or having friendly fire allowed within corp. Using webs on another ship is a hostile act which will evoke a Concord response.
You will see a green skull icon, indicating a Limited Engagement. A smaller version will appear in chat blink. Tug and freighter warps to the first gate in the route. (no webbing here - it does not work yet). Because the tug is so much faster in warp, you will out-race the freighter.
Tug jumps through, and burns back to orbit the gate. Activating the Sensor Booster with resolution script. When the freighter jumps through, it immediately commences warp to the next game. For the tug pilot, the moment that the freighter jump-cloak drops, you are locking and doubling webbing the freighter. It should instant warp the next gate of the route you have planned. The key point to note is that the freighter will appear at any random spot about 15km off the gate. Which is why I recommend a reach of 30km. (provided you have trained Electronic Attack Frigate to 5). If you using the tech1 hulls, you need to close the gap to within the web range. Which tech1/2 webs is only 10km. Which is danger time. Any bump most likely will lead to a lost freighter. (Federation Webs have a range of 14km, NEVER use these for this purpose).
Now, a bunch of things have happened to be wary of. The duel timer is reset, just keep an eye on it and renew if it happens to expire. The tug pilot earns a Weapons Timer. The red icon with a sixty second countdown. Whilst this timer is active, you can not jump or dock. And more seriously neither you or the freighter can casually log-off because of combat flag.
Usually with the weapons timer, i align the next gate under MWD. Let the timer run down to 30sec then warp to the next gate. More often than not you will out-race the freighter. Jump through the gate and repeat the process. Whether you are warping to a station, gate or bookmark FROM a gate, it will work.
A Command Ship or Battlecruiser with Interdiction Manoeuvres link will increase the range of webs, but I feel this over-complicates the process.
disclaimers: there is no Easy Esky in-game character or corporation. You use this advise your own risk. It is not perfect or a guarantee of success, just "better chance of". Should the tug get popped or connection drop, then the freighter docks.