Этап 1. Переход с массива на список.

Locomotive/Locomotive/FormLocomotive.cs

@@ -3,7 +3,6 @@ namespace Locomotive
     public partial class FormLocomotive : Form
     {
         private DrawningLocomotive _locomotive;
-
         public DrawningLocomotive SelectedLocomotive { get; private set; }
 
         public FormLocomotive()
@@ -41,7 +40,6 @@ namespace Locomotive
             SetData();
             Draw();
         }
-
         private void ButtonMove_Click(object sender, EventArgs e)
         {
             //ïîëó÷àåì èìÿ êíîïêè

Locomotive/Locomotive/MapWithSetLocomotivesGeneric.cs

@@ -55,13 +55,9 @@ namespace Locomotive
         public Bitmap ShowOnMap()
         {
             Shaking();
-            for (int i = 0; i < _setLocomotives.Count; i++)
+            foreach (var locomotive in _setLocomotives.GetLocomotives())
             {
-                var locomotive = _setLocomotives.Get(i);
+                return _map.CreateMap(_pictureWidth, _pictureHeight, locomotive);
-                if (locomotive != null)
-                {
-                    return _map.CreateMap(_pictureWidth, _pictureHeight, locomotive);
-                }
             }
             return new(_pictureWidth, _pictureHeight);
         }
@@ -80,11 +76,11 @@ namespace Locomotive
             int j = _setLocomotives.Count - 1;
             for (int i = 0; i < _setLocomotives.Count; i++)
             {
-                if (_setLocomotives.Get(i) == null)
+                if (_setLocomotives[i] == null)
                 {
                     for (; j > i; j--)
                     {
-                        var locomotive = _setLocomotives.Get(j);
+                        var locomotive = _setLocomotives[j];
                         if (locomotive != null)
                         {
                             _setLocomotives.Insert(locomotive, i);
@@ -148,11 +144,11 @@ namespace Locomotive
             int curWidth = 0;
             int curHeight = 0;
 
-            for (int i = 0; i < _setLocomotives.Count; i++)
+            foreach (var locomotive in _setLocomotives.GetLocomotives())
             {
                 // установка позиции
-                _setLocomotives.Get(i)?.SetObject(curWidth * _placeSizeWidth + 10, curHeight * _placeSizeHeight + 15, _pictureWidth, _pictureHeight);
+                locomotive?.SetObject(curWidth * _placeSizeWidth + 10, curHeight * _placeSizeHeight + 15, _pictureWidth, _pictureHeight);
-                _setLocomotives.Get(i)?.DrawningObject(g);
+                locomotive?.DrawningObject(g);
                 if (curWidth < width) curWidth++;
                 else
                 {

Locomotive/Locomotive/SetLocomotivesGeneric.cs

@@ -9,14 +9,18 @@ namespace Locomotive
     internal class SetLocomotivesGeneric <T> 
         where T : class
     {
-        private readonly T[] _places;
+        /// Список хранимых объектов
+        private readonly List<T> _places;
 
         /// Количество объектов в массиве
-        public int Count => _places.Length;
+        public int Count => _places.Count;
+        // Ограничение на количество
+        private readonly int _maxCount;
         /// Конструктор
         public SetLocomotivesGeneric(int count)
         {
-            _places = new T[count];
+            _maxCount = count;
+            _places = new List<T>();
         }
         /// Добавление объекта в набор
         public int Insert(T locomotive)
@@ -26,53 +30,47 @@ namespace Locomotive
         /// Добавление объекта в набор на конкретную позицию
         public int Insert(T locomotive, int position)
         {
-            if (position >= _places.Length|| position < 0) return -1;
+            if (position >= _maxCount|| position < 0) return -1;
+            _places.Insert(position, locomotive);
 
-            if (_places[position] == null)
-            {
-                _places[position] = locomotive;
-                return position;
-            }
-
-            int emptyEl = -1;
-
-            for (int i = position + 1; i < Count; i++)
-            {
-                if (_places[i] == null)
-                {
-                    emptyEl = i;
-                    break;
-                }
-            }
-
-            if (emptyEl == -1)
-            {
-                return -1;
-            }
-
-            for (int i = emptyEl; i > position; i--)
-            {
-                _places[i] = _places[i - 1];
-            }
-            _places[position] = locomotive;
             return position;
         }
         /// Удаление объекта из набора с конкретной позиции
         public T Remove(int position)
         {
-            if (position >= _places.Length || position < 0) return null;
+            if (position >= _maxCount || position < 0) return null;
             T result = _places[position];
-            _places[position] = null;
+            _places.RemoveAt(position);
             return result;
         }
-        /// Получение объекта из набора по позиции
+        // Индексатор
-        public T Get(int position)
+        public T this[int position]
         {
-            if (position >= _places.Length || position < 0)
+            get
             {
-                return null;
+                if (position >= _maxCount || position < 0) return null;
+                return _places[position];
+            }
+            set
+            {
+                if (position >= _maxCount || position < 0) return;
+                Insert(value, position);
+            }
+        }
+        /// Проход по набору до первого пустого
+        public IEnumerable<T> GetLocomotives()
+        {
+            foreach (var locomotive in _places)
+            {
+                if (locomotive != null)
+                {
+                    yield return locomotive;
+                }
+                else
+                {
+                    yield break;
+                }
             }
-            return _places[position];
         }
     }
 }