There are a good number of people who have the same experience as you, for a variety of reasons. These include health care workers who are rostered on for weekend shifts, emergency service workers like firemen, police, and ambulance personnel, and many others.
In addition, many people ask the same question when they are going on a holiday and they will be unable to attend Mass. For some, it is simply that their long flights do not allow them to attend any Mass. For others, their cruise liner does not put into a port where they can attend Mass.
For others, their holiday destination leaves them very far from the nearest church. And for those going on a long trek, the same can apply.
Since all of these situations are in some respects voluntary—one does not need to take that particular job, or go on that particular holiday—the question arises as to whether the person can engage in that activity, knowing they will be unable to attend Mass.
The presumption is that the person is a regular massgoer and wants to attend Mass every Sunday, so that missing Mass is an important consideration for them.
In answering the question, the following considerations should be borne in mind.
Since attending Mass is one of what are called “positive commandments,” that is, commandments which require some action to be taken rather than some action to be avoided, there can be situations in which it is not possible to fulfil them, in which case the person is excused.
The Catechism of the Catholic Church mentions some such situations: “The Sunday Eucharist is the foundation and confirmation of all Christian practice. For this reason the faithful are obliged to participate in the Eucharist on days of obligation, unless excused for a serious reason (for example, illness, the care of infants) or dispensed by their own pastor. Those who deliberately fail in this obligation commit a grave sin” (CCC 2181).
In addition to illness and the care of infants, other circumstances which could excuse someone from attending Mass are those mentioned above: matters of work, travel, holidays, etc.
The first consideration is that, if possible, one should always try to avoid putting oneself in a situation in which it will not be possible to attend Mass. The Mass is very important in our spiritual life so that non-attendance should be kept to a minimum.
But sometimes, as in the examples given above, one’s job or travel will make it impossible to attend Mass on some occasions. The important principle here is that these occasions, as far as possible, should be few.
For example, if the job requires being on duty for a whole weekend, this should generally not be more than once a month. If it is more often, as in your case, you should ask how necessary it is that you take that job.
If there are no other jobs available in your field and you need the money, you could accept the job but you should be on the lookout for another one which allows you to attend Mass more often.
Also, following what the catechism says, in order to put your conscience at ease, you might ask your pastor for a dispensation from attending Mass when you are at the mine.
As regards travel and other occasional voluntary activities which will prevent attendance, the person should first enquire as to whether there are alternatives which will allow attendance. For example, some cruise liners always have a Catholic chaplain on board and others may have one sometimes.
And some holiday destinations and resorts are known to have a Catholic church nearby, so that these should be chosen rather than one where there is no church.
If the travel involves going from one city to another on an organised tour, as far as possible tours should be chosen that allow attendance at Mass.
Since these extended holidays are usually no more than once a year, and the person has followed the indications just given without being able to find one which allows attendance at Mass on some Sundays, it would be justifiable to go on that holiday.
But these situations should be kept to a minimum.
Again, the person might ask their pastor for a dispensation for that particular occasion. And on Sundays when they cannot attend Mass, they might spend some time in prayer, perhaps using the Mass readings.