Friends, congratulations you've grown tall? What a typical Chinese sign.

So was anyone enforcing it? I cannot POSSIBLY imagine anyone enforcing it with any seriousness.

Its not a safety issue, just for reference.

There aren't enforcers so to speak like
at disneyland.

http://comperioc3.com/go/wp-content/...-this-tall.jpg

The average height for 17 year old rural Chinese girls is quoted as 157 cm. There are shorter populations, e. g. in India this is 152 cm.

Since the average is 157 cm, 149 cm is just 8 cm below average. China should have plenty of teenage girls and adult women in their upper 140s.

Now, as for the 120 cm:
is it allowed to buy a berth for someone who does not need one?
is it allowed to buy an empty berth for privacy of a compartment?

Are you essentially asking whether you can buy e.g. two tickets for (non-existing) kids to ensure you get a full 4-sleeper compartment for just the two of you?

Yes, I have bought four tickets for three people to ensure we don't have anybody else in the compartment. However, do make sure that you get four tickets for the same compartment when buying them! I have, however, never even thought about buying a children's ticket, but bought an adult one. Interesting thought though

As the conductor usually makes a headcount or even collects your tickets when you settle into your compartment, there is the slight chance that he will try to put somebody willing to upgrade into your compartment. Small risk -particularily on crowded routes, but not impossible.

Or a ticket for an existing child who however is too short to qualify for a berth.

Just how wide are the berths on Chinese trains, even in deluxe soft sleeper? And how comfortable are they for actually sleeping with a bedmate who is almost 120 cm?

For example, a family of four with 2 child tickets bought might get caught by conductor on headcount discovering that the children are under 120 cm, and forcing them to sleep with parents, to put two strangers into their bought berths. Right?

Totally unlikely.
When you buy four adult tickets you should definitely be fine - since you will receive four allocated berths. I presume you can just order four adult tickets at your hotel and nobody will ever check or even care, since you're overpaying and not trying to sneak in an 'adult' with a kid's ticket.

The key is getting four, numbered berths (which you probably won't get when buying two adults and two kids - but I don't know).

The berths are probably 70-80 cm wide and I -arguably a spoilt traveller- wouldn't want to share it with anybody; well, I generally wouldn't want to take a night train, but that's another story

For example, a standard family of two parents and one child who are used to having the child sleep in separate bed (or crib) and privacy of own room, and who can afford to pay for comfort once a year in their capacity of having found a fortune in Shanghai or Shenzhen (or being laowai) might get 4 numbered berths (3 adult and 1 child ticket) for actual headcount of 2 adults and 1 infant.

Is purchasing an empty berth for privacy of compartment something that people often get away with, or something which is expressly allowed so that the family would have grounds to stand on if challenged? Which they might well be if the train is otherwise completely packed because all other migrants want to visit their grandparents during the same holidays....

It's done with reasonable frequency by foreigners and upper class Chinese who don't mind spending the extra cash (most ordinary Chinese care more about saving money than privacy). When traveling with 2 friends in soft sleeper, we've often purchased the extra berth and partied in peace. Many middle class Chinese will buy a regular sleeper ticket for a child unless the child is very small. If you want your child to have a place of his own, buy a regular (adult) sleeper ticket and ignore child ticket. These berths in all classes are too small/narrow for two humans to share, unless humans are both 4 years old or under. Bottom line: if you purchase an adult ticket/berth, that spot is yours for the journey whether you sleep in it, put a child in it, or keep it empty. The train staff don't have the right to take away your purchased (empty) berth and give it to someone else. On the unlikely chance someone tries, stand your ground. Carriage/berth assignment is done at purchase, so once sold, that particular spot is no longer in the official database/ticket inventory for that train, for segments you purchased.

1) Make sure all the tickets you purchase are in the same compartment!
2) When the ticket taker comes around to the compartment to temporarily swap your tickets for cards/tokens, give her all the tickets even for empty berths or child-occupied. If she notices a "missing" person, just point down the hall and pantomime "bathroom"--though likely she won't notice or question. She puts the actual tickets in slots in her master book to signify those berths are taken for which segments, and to know which people to notify when to get off (some people get off at intermediate stops). And gives you a card or token with carriage/berth number on it. DO NOT LOSE THESE. She'll come back around during the last hour to swap card/token back for your tickets, which you must keep and show at the exit of the arrival station.
3) Understand that particularly when totalling the cost of buying empty berths for 4 people (assuming a soft sleeper compartment), you might want to price out 3 flight tickets (2 adult + 1 child with seat), as in this situation, plane may come out competitive, especially if you are thinking about soft sleeper on bullet trains, which can be quite expensive compared to conventional slower trains.

Buy a child to keep empty is an interesting tactic. Never thought about that one, then again I often am willing to take 6 bed berths...

You will change your tune over time.

What if you could be reasonably suspected of just that - but are actually not?

As mentioned, since the average height of 17 year old girl is 157 cm, adults in their upper 140s should not be rare.

A vaguely teenage looking female in her upper 140s might be a 12 year old trying to look 18 and succeeding, or a 17 year old who is looking more like 27, or a 27 year old who is trying to look 17 and succeeding.

So, assuming that you have a bona fide 12 year old, or a bona fide 17 year old of 149 cm. The age can be proven from ID. Is a proven 17 year old claiming the child discount something that is likely to attract enforcement efforts, to try and prove she is 151 cm pretending to be 149 cm?

I don't understand what you are trying to do. Are you
a) trying to sneak in a too-tall adult with a kids ticket
b) trying to get a full compartment for two adults and two kids

If a) don't do it.

If b) see jiejie's answer. Nobody on the train will even think about checking the height of your kids.

What train are you planning to take (on Chinese New Year?) where you expect such big crowds that they will try to besiege your compartment?

You're investing way too much energy into this endeavor. On the remote chance that your tall kids get hit with adult fares, your downside is only around 50 bucks; don't lose any sleep over this.

Could stick a couple dolls in your luggage and make them look
like kids sleeping. Similar to the fake passenger doll used to
get the HOV lanes.
Then put that "Baby on Road" sign outside your cabin.

http://m2.sourcingmap.com/smapimg/en...ker-33581n.jpg

Consider that MoR is cracking down on ticket speculation and demanding the real names of passengers, certainly on G and C trains. Are D sleeper trains also demanding real names of passengers? If yes, under what name do you book "empty berth for privacy"?