语法分析求助：The part of the ship from which the vessel is steered and its speed controlled？

您好，英语句子的并列谓语中的时态助动词通常是可以省略的。您给出的5个截图：

1）the location from which a ship is steered and (the ship's = its) speed (is) controlled;
its 替代了 the ship's，前面 is steered 是一般现在时被动语态，后面也是一般现在时被动语态，构成被动语态的 be 动词重复而被省略了。

2）the engine may be started, (may be) stopped, (may be) reversed, and (the engine's = its) speed (may be) controlled.
这一句的 后面3个 (may be) 因为重复，都被省略了。

3）the average voltage applied to the motor can be varied and (the motor's = its) speed (can be) controlled.
这一句的 (can be) 也重复了，后面的也被省略了。

4）the turbine output is adjusted and (the turbine's = its) speed (is) controlled ...
这一句的 被动语态助动词 be 并列而被省略了。

5）the current signaling system will be retained and (the train's = its) speed (will be) controlled with wayside signals.
这一句是一般将来时的被动语态，也被省略了。

可以看到这里都是谓语动词通过 and 并列了，所以构成时态的助动词基本上都被省略了。

首先感谢回答。
但仍然有些疑惑：
这种并列结构中，前后的主语都不一致的情况下，这样省略是不是有些看起来不规范，而且之前也确实只见到"and its speed controlled"这一种情况，加上我开始最早纠结的就是from which这本身就是做定语从句的例子，让我不得不怀疑这个control是不是有什么特殊用法。不知能否列举一些其他的常见动词出现这种用法的情况。

The murderer is jailed, and his rights revoked for life.
（杀人犯被关押，而且他的权利被终身剥夺。）
Having won the race, a trophy was awarded, and a reward of $100,000 given to the winner.
（赢得了比赛，获胜者被奖励了一个奖杯和十万美元。）
Having done well on her College Entrance Exam, she got accepted to a good university, and her dream fulfilled.
（高考考的很好，她被一所好大学录取了，她的梦想实现了。）
助动词省略的模式在 with 介词短语作（独立主格）的结构充当（伴随状语）是比较常见的，而您的5个句子和上面这3个句子，要是把 and 改成了 with，感觉更好理解：

1）the location from which a ship is steered with its speed controlled ...
2）the engine may be started, stopped, and reversed with its speed controlled.
3）the average voltage applied to the motor can be varied with its speed controlled
4）the turbine output is adjusted with its speed controlled
5）the current signaling system will be retained with its speed controlled with wayside signals
A）The murderer is jailed with his rights revoked for life.
但为什么用 and，而不是 with，感觉用了 and，在句中有重量，用了 with 变成伴随状语，没重量了。

您看看其他网友有没有不同的见解。